Possible Duplicate:

jQuery / Javascript replace <space> in anchor link with %20

I am getting sParameter like this :

sParameter = document.getElementById('ddParameterType').value;

If I am getting word like "Test - Text" as the ddParameterType item, then I am replacing the space in word like below:

sParameter = document.getElementById('ddParameterType').value.replace("","%20");

but it is returning a valur like %20Test - Text.
I need like Test%20-%20Text.