Search Field for Threads and Members

[GameWizard]

I have come close to getting a multiple action selector working fully for threads and members. Depending on the Drop Down value I select, it will search the inputted field in the specific board. Here is the code:

<form action="search.php?do=process" method="post">
                    <input type="hidden" name="do" value="process" />
                    <input type="hidden" name="quicksearch" value="1" />
                    <input type="hidden" name="childforums" value="1" />
                    <input type="hidden" name="exactname" value="1" />
                    <input type="hidden" name="s" value="$session[sessionhash]" />
                    <input type="text" name="query" size="25" tabindex="1001" />
                    
                    <select onChange="this.form.action=this.options[this.selectedIndex].value;">
                        <option value="search.php?do=process">All Forums</option>
                        <option value="search.php?do=process&forumchoice[]=17&childforums=1">Forum17</option>
                        <option value="memberlist.php?do=getall">Members</option>
                    </select>
                    
<input type="image" src="go.jpg" alt="$vbphrase[go]" tabindex="1004" />
                    </form>

If you notice the highlighted parts, when searching for something whilst selecting "All Forums" or "Forum17", it works 100%. However, when I use "Members". It simply outputs a blank page, and if i reload it simply lists all the users.

What I noticed while rummaging through the memberlist template is that the "name" should be set to "ausername" rather than "query". But if i change this, the search function ceases to function.

I hope there is a remedy for this problem. Essentially all i need is the ability to search for thread and members from the same input field via drop down selection.