how to add an image,checkbox,radiobutton,combobox in the grid

[charan]

hi,
i am able to load the grid from the database.i have an image field in my database,i want to display image in the grid.now it is showing undefined in the image field.can u tell me how to insert an image.
and also i want to use check box,radio button,combo box and link.what is the "type" i have to give for these fields.