Accessing Client JavaScript after Selecting Row from Grid

[Jason]

Hello,

I am currently working with Visual Studio 2008 and asp.net 3.0 I have
the following question I hope that someone can help me with:

1) I have a GridView with rows that I read from a database.

2) The user can select a row from the grid, which fires the event:

protected void MyGrid_SelectedIndexChanged(object sender,
EventArgs e)
{
<update text field on form>
<call client javascript function>
}

3) I have the <update text field on form> portion of the routine
working, but need to call the <call client javascript function> in
order to finish the processing.

4) I'm not sure how to <call client javascript function> I've seen
my web searching comments on adding something like the following in
the Page_Load:

MyMain.Attributes.add("onclick", "jsfunction();")

But this would execute the javascript first. I want the client side
JavaScript to be executed AFTER the grid does it's updating.

Would welcome any advice, suggestions, etc.?

Thanks
Jason