function echeck(str) {

var at="@"
var dot="."
var lat=str.indexOf(at)
var lstr=str.length
var ldot=str.indexOf(dot)
var resulttext='';
if (str.indexOf(at)==-1){
   resulttext = "That is not a valid email address.";
}

if (str.indexOf(at)==-1 || str.indexOf(at)==0 || str.indexOf(at)==lstr){
   resulttext = "That is not a valid email address.";
}

if (str.indexOf(dot)==-1 || str.indexOf(dot)==0 || str.indexOf(dot)==lstr){
	 resulttext = "That is not a valid email address.";
	return false
}

 if (str.indexOf(at,(lat+1))!=-1){
	 resulttext = "That is not a valid email address.";
	return false
 }

 if (str.substring(lat-1,lat)==dot || str.substring(lat+1,lat+2)==dot){
	 resulttext = "That is not a valid email address.";
	return false
 }

 if (str.indexOf(dot,(lat+2))==-1){
	 resulttext = "That is not a valid email address.";
	return false
 }

 if (str.indexOf(" ")!=-1){
	 resulttext = "That is not a valid email address.";
	return false
 }
if (resulttext!='') { 
	document.getElementById('status_email').innerHTML='<div class="divalert_email">'+resulttext+'</div>';
	document.getElementById('status_email').style.display='block';
	return false;
}
else{  return true; }
}