Widget:Calculator

<form action="" id="calculator" onsubmit="return false;">

              <fieldset>
               <legend>Calculate the time</legend>                
               <label><input type="checkbox" id="roundtrip" name="roundtrip" value="RoundTrip" />Is a round trip</label>
         
               

               <label class="calculator-label">Mean altitude of the whole route:</label> 
               <input type="text"  id="altitude" name="altitude" value=""  />
               
 
               <label class="calculator-label">Distancia horizontal en metros:</label>
               <input type="text"  id="horizontal" name="horizontal" value=""  />
               
               
               <label class="calculator-label">Metros de ascenso:</label>  
               <input type="text"  id="ascenso" name="ascenso" value=""  />
               

               <label class="calculator-label">Metros de descenso:</label> 
               <input type="text"  id="descenso" name="descenso" value=""  />
              

               </fieldset>

           <input type='submit' id='submit' value='Submit' onclick="calculateTotal()" />
       </div>  

</form> <script> function calculateTotal(){

   var theForm = document.forms["calculator"];   
   var altitude= parseInt(theForm.elements["altitude"].value);
   var horizontal= parseInt(theForm.elements["horizontal"].value);
   var ascenso= parseInt(theForm.elements["ascenso"].value);
   var descenso= parseInt(theForm.elements["descenso"].value);

   var total = (horizontal * 0.75 + ascenso * 7.2 + descenso * 2.4) * (4 * Math.pow(10, -12) * Math.pow(altitude , 3) - 9 * Math.pow(10 , -9) * Math.pow(altitude , 2) + 4 * Math.pow(10, -5) * altitude + 0,9999) * (1/3600);
   
   //display the result
   var divobj = document.getElementById('totalTime');
   divobj.style.display='block';
   divobj.innerHTML = "Total time: "+total;

}

$( document ).ready(function() {

   $('#roundtrip').click(function(){
   if (this.checked) {
       $('input#descenso').css('display', 'none')
   }

}) });

</script> <style> .calculator-label{ display: block; } </style>