// whitespace characters
var whitespace = " \t\n\r";

// Check whether string s is empty.
function isEmpty(s) { 
    return ((s == null) || (s.length == 0)) 
}

function isWhitespace (s)
{
    var i;
    // Is s empty?
    
    if (isEmpty(s)) return true;
        
        // Search through string's characters one by one
        // until we find a non-whitespace character.
        // When we do, return false; if we don't, return true.
        
        for (i = 0; i < s.length; i++) {
            
            // Check that current character isn't whitespace.
            var c = s.charAt(i);
            if (whitespace.indexOf(c) == -1) return false;
        }

    // All characters are whitespace.
    return true;
}

//  PURPOSE:  Check to see if the string passed in is a valid time.
//  A valid time is defined as a string which is postfixed with either
//  "PM" or "AM".  Next it checks to see if there is a colon in the
//  string.  If there is, it makes sure that at least one digit preceeds
//  it and two proceed it.

function IsTime(strTime)
{
    var strTestTime = new String(strTime);
    strTestTime.toUpperCase();

    var bolTime = false;

    if (strTestTime.indexOf("PM",1) != -1 || strTestTime.indexOf("AM",1))
        bolTime = true;

    if (bolTime && strTestTime.indexOf(":",0) == 0)
        bolTime = false;

    var nColonPlace = strTestTime.indexOf(":",1);
    if (bolTime && ((parseInt(nColonPlace) + 5) < (strTestTime.length - 1) || (parseInt(nColonPlace) + 4) > (strTestTime.length - 1)))
        bolTime = false;

    return bolTime;
}

function replaceAll (s, fromStr, toStr)
{
    var new_s = s;
    for (i = 0; i < 100 && new_s.indexOf (fromStr) != -1; i++) {
        new_s = new_s.replace (fromStr, toStr);
    }
    return new_s;
}

// PURPOSE:  Since we are using the single tick mark as the
// string delimiter to construct our SQL queries, a string with
// a tick mark in it will cause a SQL error.  Therefore we replace
// all "'" with "''", which eliminates the possibility of a SQL error.

function sqlSafe (s)
{
    var new_s = s;
    new_s = replaceAll (new_s, "'", "|");
    new_s = replaceAll (new_s, "|", "''");
    new_s = replaceAll (new_s, "\"", "|");
    new_s = replaceAll (new_s, "|", "''");
    return new_s;
}

function makeSafe (i)
{
    i.value = sqlSafe (i.value);
}


// isEmail (STRING s [, BOOLEAN emptyOK])
// Email address must be of form a@b.c ... in other words:
// * there must be at least one character before the @
// * there must be at least one character before and after the .
// * the characters @ and . are both required
// For explanation of optional argument emptyOK,
// see comments of function isInteger.
function isEmail (s)
{
    if (isEmpty(s)) {
        if (isEmail.arguments.length == 1) 
            return defaultEmptyOK;
        else 
            return (isEmail.arguments[1] == true);
    }
   
    // is s whitespace?
    if (isWhitespace(s)) return false;
    
    // there must be >= 1 character before @, so we
    // start looking at character position 1 
    // (i.e. second character)
    var i = 1;
    var sLength = s.length;

    // look for @
    while ((i < sLength) && (s.charAt(i) != "@")){ 
        i++
    }

    if ((i >= sLength) || (s.charAt(i) != "@"))
        return false;
    else 
        i += 2;

    // look for .
    while ((i < sLength) && (s.charAt(i) != ".")){ 
        i++
    }

    // there must be at least one character after the .
    if ((i >= sLength - 1) || (s.charAt(i) != "."))
        return false;
    else
        return true;
}


// Checks to see if a required field is blank.  If it is, a warning
// message is displayed...
function ForceEntry(val, str) {
    var strInput = new String(val.value);
    if (isWhitespace(strInput)) {
        alert(str);
        return false;
    } else {
        return true;
    }
}

//  Returns true if the string passed in is a valid number
//  (no alpha characters), else it displays an error message
function ForceNumber(objField, FieldName)
{
    var strField = new String(objField.value);
    
    if (isWhitespace(strField)) return true;

    var i = 0;

    for (i = 0; i < strField.length; i++) {
        if (strField.charAt(i) < '0' || strField.charAt(i) > '9') {
            alert(FieldName + " must be a valid numeric entry.  Please do not use commas or dollar signs or any non-numeric symbols.");
            objField.focus();
            return false;
        }
    }
    return true;
}

//  Returns true if the string passed in is a valid money
//  (no alpha characters except a decimal place), 
//  else it displays an error message
function ForceMoney(objField, FieldName)
{
    var strField = new String(objField.value);
    
    if (isWhitespace(strField)) return true;

    var i = 0;

    for (i = 0; i < strField.length; i++) {
        if ((strField.charAt(i) < '0' || strField.charAt(i) > '9') && (strField.charAt(i) != '.')) {
            alert(FieldName + " must be a valid numeric entry.  Please do not use commas or dollar signs or any non-numeric symbols.");
            objField.focus();
            return false;
        }
    }
    return true;
}

// Right trims the string...  Useful for SQL datatypes of CHAR
function RTrim(strTrim)
{
    var str = new String(strTrim);
    var i = 0;
    var c = "";
    var endpos = 0

    for (i = str.length; i >= 0 && endpos == 0; i = i - 1) {
        c = str.charAt(i);
        if (whitespace.indexOf(c) == -1)
            endpos = i;
    }
    return str.substring(0,endpos+1);
}

//  PURPOSE:  Returns true if the string is a valid date number.
//  A method is passed in (1 = month, 2 = day).  If the string is
//  nonnumeric, false is passed back.  If the day in the date string
//  is greater than 31, false is returned.  If the month is greater
//  than 12, an error is returned.
function isDateNumber(strNum,method)
{
    var str = new String(strNum);
    var i = 0;

    if (isNaN(parseInt(str)) || parseInt(str) < 0) return false;

    if (method == 2)
        if (parseInt(str) > 31)
            return false;
    if (method == 1)
        if (parseInt(str) > 12)
            return false;
    
    for (i = 0; i < str.length; i++)
        if (str.charAt(i) < '0' || str.charAt(i) > '9')
            return false;

    return true;
}

//  Displays an alert box with the passed in string...
function PromptErrorMsg(Field,strError)
{
    alert("You have entered an invalid date for " + strError + ".  Please make sure your date format is in M/D/Y format.");
    Field.focus();
}

//  Basic alert function
function PromptAlert(ErrMsg)
{
    alert(ErrMsg);
    Field.focus();
}

/* PURPOSE: Checks to see if the string is a valid date.  A valid
    date is defined as any of the following:

        MM/DD/YY, MM/DD/YYYY, M/D/YY, M/D/YYYY,
        MM-DD-YY, MM-DD-YYYY, M-D-YY, M-D-YYYY
*/

function ForceDate(strDate,strField)
{
    var str = new String(strDate.value);

    if (isWhitespace(str)) {
        return true;
        // if the field is empty, just return true...
    }

    var i = 0, count = str.length, j = 0;
    while ((str.charAt(i) != "/" && str.charAt(i) != "-") && i < count)
        i++;

    if (i == count || i > 2) {
        PromptErrorMsg(strDate,strField);
        return false;
    }

    var addOne = false;
    if (i == 2) addOne = true;

    if (!isDateNumber(str.substring(0,i),1)) {
        PromptErrorMsg(strDate,strField);
        return false;
    }

    j = i+1;
    i = 0;

    while ((str.charAt(i+j) != "/" && str.charAt(j+i) != "-") && i+j < count)
        i++;

    if (i+j == count || i > 2) {
        PromptErrorMsg(strDate,strField);
        return false;
    }
    if (!isDateNumber(str.substring(j,i+j),2)) {
        PromptErrorMsg(strDate,strField);
        return false;
    }

    j = i+3;
    i = 0;

    if (addOne) j++;

    while (i+j < count)
        i++;

    if (i != 2 && i != 4) {
        PromptErrorMsg(strDate,strField);
        return false;
    }
    if (!isDateNumber(str.substring(j,i+j),3)) {
        PromptErrorMsg(strDate,strField);
        return false;
    }

    return true;
}

function checkRadio(button, errMsg)
{
    var choice= false;
    for (counter = 0; counter < button.length; counter++) {
        if (button[counter].checked)
            choice = true;
    }
    if(!choice) {
        alert(errMsg);
        return false;
    } else {
        return true;
    }
}

//  This function determines if the string passed in is a valid
//  US zip code.  It accepts either ##### or #####-####.  If the
//  string is valid, it returns true, else false.
function isZipcode(strZip, errMsg)
{
    var z = true;
    var s = new String(strZip);

    if (s.length != 5 && s.length != 10)
        // inappropriate length
        z =  false;

    for (var i=0; i < s.length; i++) {
        if ((s.charAt(i) < '0' || s.charAt(i) > '9') && s.charAt(i) != '-')
            // inappropriate char
            z = false;
    }

    if(z) {
        return true;
    }
    else {
        alert(errMsg);
        return false;
    }
}

//  This function ensures that a field is less than or equal to the
//  Length passed in.  You must call this function with the element
//  name in your form (for example: "ForceLength(document.forms[0].txtElement)"
//  as opposed to "ForceLength(document.forms[0].txtElement.value)"
//  If the field's value is too large, an error message is displayed
//  and false is returned, else true is returned.
function ForceLength(objField, nLength, strWarning)
{
    var strField = new String(objField.value);

    if (strField.length > nLength) {
        alert(strWarning);
        return false;
    } else {
        return true;
    }
}

function ValidateRanking() {
    // This function ensures document.forms[0].nRanking.value >=1 && <= 10
    if (parseInt(document.forms[0].nRanking.value) >= 1 && parseInt(document.forms[0].nRanking.value) <=10)
        return true;
    else
        return false;
}