pagging on gridview ?

Question

i have a rowcommand to bind a grid using different conditions

how to apply paging on a gridview.

 

for eg.

protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
{
if (e.CommandName == "a")
{
bindgrid
}

if (e.CommandName == "b")
{
bindgrid
}