window.onload = initForms;

function initForms() {
//	alert("check form init");
	for (var i=0; i< document.forms.length; i++) {
		document.forms[i].onsubmit = function() {
			return checkNewUser();	
		}
	}
}

function checkNewUser() {
	var allGood = true;
	var allTags = document.getElementsByTagName("input");
	for (var i=0; i<allTags.length; i++) {
		if (!validTag(allTags[i])) {
			allGood = false;	
		}
	}
	return allGood;
	
	function validTag(thisTag) {	// is inside validForm function to be able to pass information
		var outClass = "";
		var allClasses = thisTag.className.split(" ");
		for (var j=0; j<allClasses.length; j++) {
			outClass +=validBasedOnClass(allClasses[j]) + " ";	
		}
		
		thisTag.className = outClass;
		
		if (outClass.indexOf("invalid") > -1) {	// invalid = error is in that string
			thisTag.focus();	// forces to be in focus, puts cursor into field
			if (thisTag.nodeName == "INPUT") {
				thisTag.select();	
			}
			return false;
		}
		return true;
		
		
		function validBasedOnClass(thisClass) {
			var classBack = "";	
			switch(thisClass) {
				case "":
				case "invalid":
					break;
				case "reqd":	// this input field is required class
					if (allGood && thisTag.value == "") {
						classBack = "invalid ";	
					}
					classBack += thisClass;
					break;

				case "email":
					if (allGood && !validEmail(thisTag.value)) {
						classBack = "invalid ";	// not valid email address	
					}
					classBack +=thisClass;
					break;
				default:
					classBack += thisClass;
			}
			return classBack;
		}
		
		function validEmail(email) {	// checks whether email addr is valid, does not check for all problems
			var invalidChars = " /:,;";
			
			if (email == "") {
				return false;	
			}
			for (var k=0; k<invalidChars.length; k++) {
				var badChar = invalidChars.charAt(k);
				if (email.indexOf(badChar) > -1) {	// if invalid chars are in there return false
					return false;	
				}
			}
			var atPos = email.indexOf("@",1);	// is @ after the first character?
			if (atPos == -1) {
				return false;	
			}
			if (email.indexOf("@",atPos+1) != -1) {	// is there more than one @ in there?
				return false;	
			}
			var periodPos = email.indexOf(".",atPos);
			if (periodPos == -1) {
				return false;	
			}
			if (periodPos+3 > email.length) {	// position of . needs to be not at end but at least 2 chars before end
				return false;	
			}
			return true;
			
		}
	}
}