firing onclick event of button1 from button2

i have 2 buttons on a page button1 & btndelete

i have a function in javascript to get the value

 function Button1_onclick()

{

get the value

}

<input id="Button1" type="button" value="button" onclick="return Button1_onclick()" />

when i click i get the value as needed in a hidden field

but i want to use this value when the user clicks btndelete which has server side code for delete

 <asp:Button ID="cmddelete" runat="server" Text="Delete" Width="87px" Font-Bold="True"                     Font-Size="Small" OnClick="cmddelete_Click"  />

i dont want the user to click 2 butttons to achieve delete functionality

i need everything on deleteclick , how can i have a server side code & script for same button