// JavaScript Document
function validateEmail(elementValue){      
     var emailPattern = /^[a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4}$/;
     return emailPattern.test(elementValue); 
}    
function validate(form){
    if(form.yourname.value.length<=3){
        alert("Sorry we require your name.");
        form.yourname.focus();
        return false;
    }
    if(form.youremail.value.length<=3){
        alert("Sorry we require your email address");
        form.youremail.focus();
        return false;
    }
    else{
        if(!validateEmail(form.youremail.value)){
            alert("Sorry email not in correct format please re-enter ");
            form.youremail.focus();
            return false;
        }
    }
    if(form.friendname.value.length<=3){
        alert("Sorry we require your friends name.");
        form.friendname.focus();
        return false;
    }
    if(form.friendemail.value.length<=3){
    	alert("Sorry we require your friends email address");
    	form.friendemail.focus();
        return false;
    }
    else{
        if(!validateEmail(form.friendemail.value)){
             alert("Sorry email not in correct format please re-enter ");
             form.friendemail.focus();
             return false;
        }
   }
   return true;
}