function checkRequired(which, alertText, formname){
	var buy=new Array('first_name','last_name','street','street_hn','post_code','city','country','email','pay_type');
	var mailorder= new Array('first_name','last_name','street','street_hn','post_code','city','cardtype','card_no1','card_no2','card_no3','card_no4','date_month','date_year');
	var pass=true;
   for (i=0;i<which.length;i++){
      var tempobj=which.elements[i]
      if(formname=='buy'){if( js_in_array(tempobj.name,buy) && tempobj.value==''){pass=false;break;}}
      else if(formname=='mailorder'){if( js_in_array(tempobj.name,mailorder) && tempobj.value==''){pass=false;break;}}
   }
	if (!pass){alert(alertText);return false;}else{return true;}
}
function js_in_array(the_needle, the_haystack){
   var the_hay = the_haystack.toString();
   if(the_hay == ''){return false;}
   var the_pattern = new RegExp(the_needle, 'g');
   var matched = the_pattern.test(the_haystack);
   return matched;
}