function checkForm(f){
	var errors="";

	if(!f.sender_fname.value){errors+="\n + Your First Name";}
	if(!f.sender_lname.value){errors+="\n + Your Last Name";}
	if(!f.sender_email.value){
		errors+="\n + Your email";
	}else if(f.sender_email.value != f.sender_email_confirm.value){
		errors+="\n + Confirm your email";
	}

	for(i=1;i<=5;i++){
		name = eval("f.receiver_name_"+i+".value");
		email = eval("f.receiver_email_"+i+".value");
		email_confirm = eval("f.receiver_email_confirm_"+i+".value");
		if(name || email){
			if(!name){errors+="\n + Name #"+i;}
			if(!email){
				errors+="\n + Email address #"+i;
			}else if(email != email_confirm){
				errors+="\n + Confirm email #"+i;
			}		
		}
	}


	if(errors){
		alert("The following fields need to be completed:"+errors);
		return false;
	}
	return true;
}