Anchor tag inside an <li> event triggering issue

I have a horizontal menu plugin in which i am adding anchor tag to the <li> in order to get the menu items. i am using onmouseo开发者_开发问答ver event of anchor tag to get the menu items list. my problem is whenever i am moving mouse over the content i am getting the submenu (ie, the event gets fired) but if i move the mouse on the empty space on the right side of the menu item then the event is not triggering ,when used firebug i found that empty space is belongs to the parent container which is <li>.I cannot use onmouseover of <li> since my logic is different.I just want to expand the size of my anchor tag to the parent <li>. please give me a solution.

<li class="">
    <a href="#" class="accessible" onmouseover="loadSublevelMenu('${url}','${menuVar}',event);">${menuName}&raquo;</a>
</li>

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Add the following style to the a tag style="display:block"