function selectdPopImage() {
  // create an array of all possible images
  var dPopArray = new Array('http://www.hlthss.gov.nt.ca/sites/drop_the_pop/images/header/better_smile_header.jpg',
  'http://www.hlthss.gov.nt.ca/sites/drop_the_pop/images/header/healthy_environment_header.jpg',
  'http://www.hlthss.gov.nt.ca/sites/drop_the_pop/images/header/better_concentration_header.jpg',
  'http://www.hlthss.gov.nt.ca/sites/drop_the_pop/images/header/strong_bones_header.jpg',
  'http://www.hlthss.gov.nt.ca/sites/drop_the_pop/images/header/keep_traditions_header.jpg',
  'http://www.hlthss.gov.nt.ca/sites/drop_the_pop/images/header/good_health_header.jpg'); 
  // select a random num between 0 and length of the array
  var randomNum = Math.floor(Math.random() * dPopArray.length);
  // assign a random array entry to the src of the image 
  document.getElementById("dropthePop").src = dPopArray[randomNum]; 
}

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 ID")
		   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					
	}

function ValidateForm(){
	var emailID=document.school.Email
	
	if ((emailID.value==null)||(emailID.value=="")){
		alert("Please Enter your Email ID")
		emailID.focus()
		return false
	}
	if (echeck(emailID.value)==false){
		emailID.value=""
		emailID.focus()
		return false
	}
	return true
	
 }