Oh right, just to clarify you want it to hide "Search All" when the input box is clicked? If i'm right in assuming that:
Code:
<input class="ibox_search" type='text' name='search' value='Search All' style='width:300' onfocus="this.value=='Search All'?this.value='':this.value=this.value;" onblur="this.value==''?this.value='Search All':this.value=this.value;">
It makes sence to use onfocus rather than onclick because a user can tab to the input box aswell... And the onblur code simply checks to see if the text box is empty and replaces that with "Search All" if it is.
Cheers,
Jamey
p.s. Welcome to tsf =]