function sf(txt)
{
 document.write(txt);
};


function  mark_form(n,elem)
{
 if (n==1) elem.style.background="#fbe5e5"; else elem.style.background="#FFF";
};


function checkform(formid)
{

 var required_arr=as.$(".required");
 var required_flag=0;


 for (var i=0; i<required_arr.length; i++)
  {
   switch(required_arr[i].type)
    {
     default:

       if (required_arr[i].value=='')
        {
         required_flag=1;
         mark_form(1,required_arr[i]);
        } else mark_form(0,required_arr[i]);

     break;

     case("checkbox"):

       if (required_arr[i].checked==false)
        {
         required_flag=1;
         mark_form(1,required_arr[i]);
        } else mark_form(0,required_arr[i]);

     break;
    };
  };

 if (required_flag) alert("Необходимо заполнить обязательные поля"); else document.getElementById(formid).submit();
};