function requiredfield(elementId, errorElementId, msg, isAlphaNum)
{
	var string = trimWhitespace(elementId.value);
	if (  string == '' )	{
		errorElementId.innerHTML = msg;
		return 0;
	} else if  ( isAlphaNum == true ) {
		var charPos = string.search("[^A-Za-z0-9_]");

		if ( charPos >= 0 )
		{
			errorElementId.innerHTML = 'Special characters are not allowed';
			return 0;
		} else 	{
			errorElementId.innerHTML = '';
			return 1;
		}	
	} else 	{
		errorElementId.innerHTML = '';
		return 1;
	}
}

function validateNo(elementId, errorElementId, invalidMsg)
{
	var string = trimWhitespace(elementId.value);
	var charpos = string.search("[^0-9]");
	if ( charpos >= 0 )	{
		errorElementId.innerHTML = invalidMsg;
		return 0;
	}
	errorElementId.innerHTML = '';
	return 1;
}

// Check that an email address is valid based on RFC 821 (?)
function isValidEmail(address) {
	if (address != '' && address.search) {
      if (address.search(/^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/) != -1) return true;
      else return false;
	}

   // allow empty strings to return true - screen these with either a 'required' test or a 'length' test
   else return true;
}

// Remove leading and trailing whitespace from a string
function trimWhitespace(string) {
	var newString  = '';
	var substring  = '';
	var beginningFound = false;

	// copy characters over to a new string
	// retain whitespace characters if they are between other characters
	for (var i = 0; i < string.length; i++) {

		// copy non-whitespace characters
		if (string.charAt(i) != ' ' && string.charCodeAt(i) != 9) {

			// if the temporary string contains some whitespace characters, copy them first
			if (substring != '') {
				newString += substring;
				substring = '';
			}
			newString += string.charAt(i);
			if (beginningFound == false) beginningFound = true;
		}

		// hold whitespace characters in a temporary string if they follow a non-whitespace character
		else if (beginningFound == true) substring += string.charAt(i);
	}
	return newString;
}

//Validation for get result form
function validateGetResultForm()
{
	var regNo = document.getElementById('regNo');
	var regNoError = document.getElementById('regNoError');

	var standard = document.getElementById('standard');
	var standardError = document.getElementById('standardError');
	var status = 1;	


	if ( requiredfield(regNo, regNoError, 'Reg. No. required') == 0 ) { 
		status = 0;
	} else if ( validateNo(regNo, regNoError, 'Invalid reg. no.') == 0 ) { 
		status = 0;
	} else if ( regNo.value.length != 6 ) {
			regNoError.innerHTML = 'Invalid reg. no.';
			status = 0;
		} else { regNoError.innerHTML = ''; }

	if( standard.value == '0' )
	{
	 	document.getElementById('standardError').innerHTML = '&nbsp;Standard Required';
		status = 0;
	}
	else
	{
		document.getElementById('standardError').innerHTML = '';
	}

	if ( status == 0 ) { return 0; } else {	return 1; }
}


function handleResEnter()
{
	if ( validateGetResultForm() == 0 )
	{
		return false;
	}
	return true;
}