// JavaScript Document
 
function compute1() {
   show("BMIErrorTag",""); 
   var f = document.bmi_input;
   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;
   var spl = checkSpl(w); 
   
   if(w.length==0)
   {
       show("BMIErrorTag","Please enter your weight."); 
      return;
   }
   if(spl==false)
   {
      show("BMIErrorTag","Please use numbers."); 
      return;
    }
    var wordCheck = chkw(w);
    
   if (wordCheck == true){
     f.bmi.value = cal_bmi(w, i);
   } else { 
     show("BMIErrorTag","Please use numbers"); 
   }
   
   
   
   // Set cookies for future views of this page
   // Expires when user closes browser
   document.cookie = "bmi=" + f.bmi.value;
   document.cookie = "wt=" + f.wt.value;
   document.cookie = "htf=" + f.htf.selectedIndex;
   document.cookie = "hti=" + f.hti.selectedIndex;
}

function chkw(w) {
    var result = true
    var len = w.length;
    var validChars = "0123456789.";
    for (var i = 0; i < len; i++) 
    {
       var nos = validChars.indexOf(w.charAt(i));
       
        if (nos == -1)
             {
            result = false; 
            break;
              }
            
        }
    return result;
}

function cal_bmi(lbs, ins) {
   h2 = ins * ins;
   bmi = lbs/h2 * 704.5 // to convert to metric
   f_bmi = Math.floor(bmi);
   diff  = bmi - f_bmi;
   diff = diff * 10;
   diff = Math.round(diff);

   if (diff == 10) {
      // Need to bump up the whole thing instead
      f_bmi += 1;
      diff = 0;
   }

   bmi = f_bmi + "." + diff;
   return bmi;
}

function checkSpl(w) {
var result = true
var len = w.length;
var inValidChars = "*|,\":<>[]{}`\';()@&$#%!^~`";
    for (var i = 0; i < len; i++) 
    {
       var splch = inValidChars.indexOf(w.charAt(i));
       
        if (splch != -1)
             {
            result = false; 
            break;
              }
            
        }
    return result;
}

function show(ele,content) {
      var srcElement = document.getElementById(ele);
      if(srcElement != null) {
       srcElement.innerHTML=content;
      }
}