function validate_required(field,alerttxt){
	with (field){
		if (value==null||value=="")
		  {alert(alerttxt);return false;}
		else {return true}
	}
}

function validate_email(field,alerttxt){
	with (field){
		apos=value.indexOf("@");
		dotpos=value.lastIndexOf(".");
		if (apos<1||dotpos-apos<2){alert(alerttxt);return false;}
		else {return true;}
	}
}

function validate_form(thisform){
	with (thisform){
		
		if (validate_required(name,"Enter your name")==false)
		  {name.focus();return false;}
		
		else if (validate_email(email,"Not a valid e-mail address!")==false)
		  {email.focus();return false;}
		
		else if (validate_required(category,"Select a category")==false)
		  {category.focus();return false;}
		
		else if (validate_required(message,"message must be filled out!")==false)
		  {message.focus();return false;}
		
	}
}