How to customize the options of a listgrid for getting custom dialogs on click

[sibasish.palo]

How to customize the following options (image attached to the post) to get custom dialogs on click of the following menu items

Thanks in advance

[sibasish.palo]

i have tried over riding getHeaderContextMenuItems() method and added clickhandlers to the menu items, when clicked on a column header it gives the menu but when clicked on the options available in the list its defaulting to the last column,its giving the custom dialogs from the last column available in the grid.

Note: if i right click on the grid column its giving the option from the column on which i am clicking but if i am using left click to select the menus its giving the above behavior.

Please help.