Slide 24

window.onload = function() {
document.forms[0].onsubmit = validForm;
}
function validForm() {
var allGood = true;
var allTags = document.forms[0].getElementsByTagName("*");
for (var i=0; i<allTags.length; i++) {
if (!validTag(allTags[i])) {
allGood = false;
}
}
return allGood;
function validTag(thisTag) {
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) {
invalidLabel(thisTag.parentNode);
thisTag.focus();
if (thisTag.nodeName == "INPUT") {
thisTag.select();
}
return false;
}
return true;
function validBasedOnClass(thisClass) {
var classBack = "";
switch(thisClass) {
case "":
case "invalid":
break;
case "reqd":
if (allGood && thisTag.value == "") {
classBack = "invalid ";
}
classBack += thisClass;
break;
case "radio":
case "isNum":
case "isZip":
case "email":
classBack += thisClass;
break;
default:
if (allGood && !crossCheck(thisTag,thisClass)) {
classBack = "invalid ";
}
classBack += thisClass;
}
return classBack;
function crossCheck(inTag,otherFieldID) {
if (!document.getElementById(otherFieldID)) {
return false;
}
return (inTag.value != "" || document.getElementById(otherFieldID).value != "");
}
}
}
function invalidLabel(parentTag) {
if (parentTag.nodeName == "LABEL") {
parentTag.className += " invalid";
}
}
}