function calc() {

   var w = document.size.width.value;
   var x = w*document.size.profile.value/.127;
   var y = document.size.wheel.value * 100;
   document.size.ov_diamA.value = Math.round(x + y)/100;
   document.size.ov_diamB.value = Math.round((x + y)*25.4/100);

   var w1 = document.size.width1.value;
   var x1 = w1*document.size.profile1.value/.127;
   var y1 = document.size.wheel1.value * 100;
   document.size.ov_diamA1.value = Math.round(x1 + y1)/100;
   document.size.ov_diamB1.value = Math.round((x1 + y1)*25.4/100);

   document.size.difference.value=document.size.ov_diamB1.value-document.size.ov_diamB.value;
   document.size.diffpercent.value=(Math.round(10000*(document.size.ov_diamB1.value-document.size.ov_diamB.value)/document.size.ov_diamB.value))/100;

} //EoFn