// FORM VALIDATION
function checkForm(){
	//document.getElementById("formError").style.display = 'none';
	var error = "";
	var elems = document.warningForm.getElementsByTagName("input");
	for(i=0; i<elems.length; i++){
		if(elems[i].type == "text"){
			error = addValidityIndicator(elems[i]);
		}
	}
	
	if(error != ""){
		return false;
	}
	
	return true;
}

function validateEmpty(elem, errorName, exactLength){
	var error = "";
	if(exactLength != null){
		if(elem.value.length != exactLength){
			error = "The "+errorName+" must be "+exactLength+" characters long.\r\n";
		} 
	} else {
		if(elem.value == ""){
			error = "Please enter your "+errorName+".\r\n";
		}
	}
	
	return error;
}

function validateEmail(elem, errorName){
	var error="";
    var tfld = trim(elem.value);                        // value of field with whitespace trimmed off
    var emailFilter = /^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,4})$/;
    var illegalChars= /[\(\)\<\>\,\;\:\\\"\[\]]/ ;
   
    if (elem.value == "") {
        error = "Please enter your "+errorName+".\r\n";
    } else if (!emailFilter.test(tfld)) {  
        error = errorName+" is not a valid e-mail address.\r\n";
    } else if (elem.value.match(illegalChars)) {
        error = errorName+" contains illegal characters.\r\n";
    }
    return error;
}

function trim(s) {
  return s.replace(/^\s+|\s+$/, '');
}

function addValidityIndicator(obj){
	var error = "";
	var image = new Object();
	
	if(obj.name == "warningFormSecurityCode"){
		error = validateEmpty(obj, "Security Code", 5);
	} else if(obj.name == "warningFormNameField") {
		error = validateEmpty(obj, "Name");
	} else if(obj.name == "warningFormEmailField"){
		error = validateEmail(obj, "Email");
	}
	
	if(error == ""){
		image.src = "http://www.i-studentgroup.com/includes/libs/images/tick.png";
		image.alt = "Correct";
		image.className = "tick";
	} else {
		image.src = "http://www.i-studentgroup.com/includes/libs/images/cross.png";
		image.alt = error;
		image.className = "cross";
	}
	var objRef = "#"+obj.id;
	if(document.getElementById(obj.id+"TC") != null){
		objRef += "TC";
		jQueryDetection(objRef).attr("src",image.src);
		jQueryDetection(objRef).attr("class",image.className);
		jQueryDetection(objRef).attr("alt",image.alt);
	} else {
		jQueryDetection(objRef).after('<img id="'+obj.id+'TC" class="'+image.className+'" src="'+image.src+'" alt="'+image.alt+'" width="20px" height="20px" />');
	}
	
	if(error == ""){
		return "";
	} else {
		
	} return "error";
}