function isNumberKey(evt)
      {
         var charCode = (evt.which) ? evt.which : event.keyCode
         if (charCode!=46 && charCode!=8 && (charCode < 48 || charCode > 57))
            return false;

         return true;
      }
function mi1()
{
var m = document.form1.m.value;
var r = document.form1.r.value;
if((m=="" && r=="")||(m=="" || r==""))
{
alert("please enter value for all fields");
}
else
{
var r=r*r;
document.form1.mi.value=m*r;
}
}