function result() {
   var frm1 = document.bmr_input;
   var gender = frm1.optgen.options[frm1.optgen.selectedIndex].value;
   var age = frm1.txtage.value;
   var inch1 = parseInt(frm1.optfeet.options[frm1.optfeet.selectedIndex].value * 12);
   var inch2 = parseInt(frm1.optinch.options[frm1.optinch.selectedIndex].value);
   var ht = inch1 + inch2;
       wht = frm1.txtwht.value;

   if (chk(wht) && chk(age)){
      frm1.txtbmr.value = calculate(wht, ht, gender, age);
   } else { 
      alert("Please enter all fields"); 
   }
  }

function chk(i) {
   if (isNaN(parseInt(i))) {
      return false;
   } else if (i < 0) {
      return false;
   }
   else {
      return true;
   }
}

function calculate(wt, inh, gndr, age) {
   hcm = inh * 2.54; 
   wkg = wt * 0.4536;
   if (gndr == "F") {
	   	bmr = 655 + 9.6 * wkg + 1.8 * hcm - 4.7 * age;
	} 
   else {
	bmr = 66 + 13.7 * wkg + 5 * hcm - 6.8 * age;
   }

   bmr1 = Math.floor(bmr);
   deci = bmr - bmr1;
   deci = deci * 10;
   deci = Math.round(deci);
   if (deci == 10) { 
       bmr1 += 1;
      deci = 0;
   }
   bmr = bmr1 + "." + deci;
   return bmr;
}