Help with JavaScript

I'm trying to modify a javascript in the forum but I need some help.

this is what I have

<script language="javaScript">

var test = "This is a Test";

var newString = test.replace(" ","");

</script>

I'm trying to delete the white spaces in the variable test but doing what I did it only deletes the first white space but the other ones don't go. so currently the newString variable comes with (Thisis a Test). How can I delete all the other blank spaces??

Thanks

Carlos