<Asp:Menu SubMenu overlapes the frame

[hemantn]

I am using asp: menu control in my web application which i am populating the menu items dynamically through dataset, now the child item of this menu get overlapped because i am using the frames in the web application

my default.aspx contains below frameset code
<frameset cols="10%,*" framespacing="0" frameborder="NO">
<frame name="leftFiller" >
<frameset rows="115px,*" frameborder="NO" border="0" framespacing="0">
<frame src="OT_Top_Page.aspx" name="topFrame" scrolling="no">
<frameset cols="142,*" frameborder="NO" border="0" framespacing="0">
<frame src="OT_Left_Menu.aspx" name="leftFrame" scrolling="no">
<frame src="OT_EmpSSP_MainPage.aspx" name="mainFrame">
</frameset>
</frameset>
<frame name="rightFiller" >
</frameset>

Now the OT_Left_Menu.aspx contains the code asp:menu code to generate the Menu Items and the sub menu item should display adjacent to parent menu item and which get overlapped on the same Parent menu item since on right hand side the frame border does exist which i cannot increase the width
is there any solution to populate the submenu and could overflow on rightframe (mainframe).

THank you