JS Help

Ok,

I have this code, which is meant to add something on to the value currently displayed.

Heres the code so far:

HTML Code:

---

function calc(hcs)
{
try{
 var cur = document.getElementById("calcscreen").innerHTML;
  cur = cur+hcs;
  document.getElementById("calcscreen").innerHTML = cur;
  }
  catch(err)
  {
  alert(err);
  }
}
function cls()
{
document.getElementById("calcscreen").innerHTML = 0;
}

---

Whats going wrong is that if we use the calc(2.0); function, if the initial display was 0 it would become

02

Then if we do again it would become

022

I think its making the variables string and as such, not adding correctly, if this is the case, does anyone have the code to turn them back into integer/single?

Thanks for any help =]

Sorry to double post,

But does anyone know a way to get round this error?