Changing Visibilty of button?

hello,
I have one form on which gridview is their.On gridview one add button and one edit button is there.
when i clicked on add button the form will be redirected on addedit form.On addedit form two buttons are there add and edit.i want to visible only add button
while clicking on add button of the gridview and similarly when i clicked on edit button of the gridview only edit button should be visible for addedit form.....

how can i set visibility of button on different event ...?

and one thing is that when i clicked on edit button of the gridview the all information will be inserted on addedit form as per selected row of the gridview ...i am creaing one method for that as show().

and i m called that method on page load method as like

protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
show();
}
}

private void show()
{
btnadd.visible=false;
btnedit.visible=true;
.....
}

thank you.