function isEmail(aString) {
	var aChar  = null;
	var atSign = null;
	var period = null;
	var status = true;
	if(aString.length <= 6) {
		status = false;
	}	
	else {
		for(var i=0; i<=aString.length; i++) {
			aChar = aString.charAt(i)
			if(aChar=="@") {
				atSign = atSign + 1;
				if(atSign > 1) {
				    status = false;
				    break;
	        		}
			}
			else if(aChar==".") {
				period = period + 1;
			}
		}
	}
	if(atSign!=1||period<1) {
		status = false;
	}
return status;
}