function cal_bmi(lbs, ins){

   h2 = ins * ins;
   bmi = lbs/h2 * 703
   f_bmi = Math.floor(bmi);
   diff  = bmi - f_bmi;
   diff = diff * 10;
   diff = Math.round(diff);

   if (diff == 10){
      // Add up to next
      f_bmi += 1;
      diff = 0;
   }



   bmi = f_bmi + "." + diff;

   return bmi;

}



function compute(){
   var f = top.document.forms[0];
   var fi = parseInt(f.htf.options[f.htf.selectedIndex].value * 12);
   var ii = parseInt(f.hti.options[f.hti.selectedIndex].value);
   var i = fi + ii;

 

   w = f.wt.value;
   if (chkw(w)){
      f.bmi.value = cal_bmi(w, i);
   } else { alert("Please enter a number for your weight."); }

}



function chkw(w){
   if (isNaN(parseInt(w))){
      return false;
   } else if (w < 0){
      return false;
   }

   else{
      return true;
   }

}