C# webbrowser control - input click

I have this form

<form method='POST' action='1.php'>
    <input type='hidden' name='min' value='24'>
    <input type='hidden' name='max' value='27'>
    <input type='hidden' name='do_some' value='1'>

    <input type='image' name='do_some' class='image cmd' src='images/1.png' alt='1'
                        onMouseOver="doImage()"/ >
    <input type='image' name='do_search' class='image cmd' src='imag开发者_Go百科es/2.png' alt='2'
                        onMouseOver="doImage()"/ ></form>

but I need to click on "input name='do_search'" and when I do

webBr.Document.All.GetElementsByName("do_search").Cast<HtmlElement>().First().InvokeMember("click");

it's always click "input name='do_some'".

I think all I need its male a click with X and Y... but here new problem I can not find how... ?

You have two inputs with the same name.

 <input type='hidden' name='do_some' value='1'>  
 <input type='image' name='do_some' class='image 
cmd' src='images/1.png' alt='1' onMouseOver="doImage()"/ >