function IsNumeric(sText)

{
   var ValidChars = "0123456789.";
   var IsNumber=true;
   var Char;

 
   for (i = 0; i < sText.length && IsNumber == true; i++) 
      { 
      Char = sText.charAt(i); 
      if (ValidChars.indexOf(Char) == -1) 
         {
         IsNumber = false;
         }
      }
   return IsNumber;
   
   }
   
   function check(theForm) { 
   var c = document.getElementById("cantidad").value;
   if (IsNumeric(c) && c.length >= 1) { theForm.submit(); return true; } 
   else { alert("Quantity must be numeric"); return false; }
   
   }
   
   function cart(theForm) { 
   var c = document.getElementById("code").value;
   if (c.length >= 1) {  theForm.submit();  } 
   else { location.href="step1.php"; }
   }
   function remover() { 
   this.removere.submit;
   }