// JavaScript Document
function showTab(element_to_show) {
	var element = document.getElementById(element_to_show);
	if(element.style.display == 'block'){
		element.style.display = 'none';
	}else{
		hideTab();	
		element.style.display = 'block';
	}	
}
	
function hideTab() {
	
	var count = 1;
	var tab = 'sub'+count;
	while(document.getElementById(tab) != null){
		document.getElementById(tab).style.display = 'none';
		count++;
		tab = 'sub'+count;
	}
	
}

function changeImage(name) {
	newImage = "url(images/half-circle-orange.gif)";
	document.getElementById(name).style.backgroundImage = newImage;
}

function changeBack(name) {
	newImage = "url(images/half-circle.gif)";
	document.getElementById(name).style.backgroundImage = newImage;
}

function doPreload(menu_to_open)
{  
  preload1 = new Image();
  preload1.src = "images/half-circle-orange.gif";
}

function ValidateForm(){
	var emailID=document.newsletter.email;
	var name = document.newsletter.name;
	
	if ((name.value==null)||(name.value=="")){
		alert("Please Enter your Name")
		name.focus()
		return false
	}
	
	if ((emailID.value==null)||(emailID.value=="")){
		alert("Please Enter your Email Address")
		emailID.focus()
		return false
	}
		
	if (echeck(emailID.value)==false){
		emailID.value=""
		emailID.focus()
		return false
	}
	return true
 }

function echeck(str) {

		var at="@"
		var dot="."
		var lat=str.indexOf(at)
		var lstr=str.length
		var ldot=str.indexOf(dot)
		if (str.indexOf(at)==-1){
		   alert("Invalid E-mail Address")
		   return false
		}

		if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
		   alert("Invalid E-mail ID")
		   return false
		}

		if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
		    alert("Invalid E-mail ID")
		    return false
		}

		 if (str.indexOf(at,(lat+1))!=-1){
		    alert("Invalid E-mail ID")
		    return false
		 }

		 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
		    alert("Invalid E-mail ID")
		    return false
		 }

		 if (str.indexOf(dot,(lat+2))==-1){
		    alert("Invalid E-mail ID")
		    return false
		 }
		
		 if (str.indexOf(" ")!=-1){
		    alert("Invalid E-mail ID")
		    return false
		 }

 		 return true					
}