Forms Data Controls :: Fetch Gridview Edit Template Field In Custom Validator?

I have an edit template on gridview which opens a text box and button with a custom validator .

On button press I have to validate the text in edit item template with a text field in gridview row template.

I am having a hard time fetching the data of the edit template textbox. Even though both custom validator and textbox are in same edit item template but intellisense is not picking it up.

Also the custom validator server_validate event is using "object source" instead of "object sender"

How do I fetch the edit item template text for comparison

I am doing this as

protected void CustomValidator1_ServerValidate(object source, ServerValidateEventArgs args)
{
GridViewRow gvrow = (GridViewRow)(source as Control).Parent.Parent;
int index = gvrow.RowIndex+1;
// TextBox txttmp=(TextBox)
Label lbl = (Label)gvComp.Rows[index].FindControl("lblSecShare");
decimal CSh = Convert.ToDecimal(lbl.Text);
}