function kontrol() {

if (document.form2.name.value=="") { alert("Ad alanini bos birakmayiniz !"); }
if (document.form2.boy.value=="") { alert("Boy alanini bos birakmayiniz !"); }
if (document.form2.kilo.value=="") { alert("Kilo alanini bos birakmayiniz !"); }

}

 function isNumberKey(evt)
      {
         var charCode = (evt.which) ? evt.which : event.keyCode
         if (charCode > 31 && (charCode < 48 || charCode > 57))
            return false;

         return true;
      }