// Returns true if character c is a digit 
// (0 .. 9).
function isDigit (c){
	return ((c >= "0") && (c <= "9"))
}

// Validates Form
function checkContactForm(formobj){
	//1) Enter name of mandatory fields
	var fieldRequired = Array("firstName","lastName","email");
	//2) Enter field description to appear in the dialog box
	var fieldDescription = Array("First Name","Last Name","Email");
	//3) Enter dialog message
	var alertMsg = "Please complete the following fields:\n";
	
	var l_Msg = alertMsg.length;
	
	for (var i = 0; i < fieldRequired.length; i++){
		var obj = formobj.elements[fieldRequired[i]];
		if (obj.type == null){
			var blnchecked = false;
			for (var j = 0; j < obj.length; j++){
				if (obj[j].checked){
					blnchecked = true;
				}
			}
			if (!blnchecked){
				alertMsg += " - " + fieldDescription[i] + "\n";
			}
			continue;
		}
		if (obj){
			switch(obj.type){
			case "checkbox":
				if (obj.value == "" || obj.value == null) {
					alertMsg += " -- " + fieldDescription[i] + "\n";
				}
				break;
			case "select-one":
				if (obj.selectedIndex == -1 || obj.options[obj.selectedIndex].text == ""){
					alertMsg += " - " + fieldDescription[i] + "\n";
				}
				break;
			case "select-multiple":
				if (obj.selectedIndex == -1){
					alertMsg += " - " + fieldDescription[i] + "\n";
				}
				break;
			case "text":
			case "textarea":
				var digit = false;
				if (obj.value == "" || obj.value == null){
					alertMsg += " - " + fieldDescription[i] + "\n";
				}
				break;
			default:
				if (obj.value == "" || obj.value == null){
					alertMsg += " - " + fieldDescription[i] + "\n";
				}
			}
		}
	}

	if (alertMsg.length == l_Msg){
		return true;
	}else{
		alert(alertMsg);
		return false;
	}
}