Hi,
write a button click event for the btnAddProduct. In the button click write the below code,
Button btn = (Button)sender;
GridViewRow gvReference = (GridViewRow)(btn.Parent.Parent);
String strLabel1 = ((Label)gvReference.FindControl("Label1")).Text.ToUpper();
...
...
or
Call a javascript function on the btnAddProduct click to get the values.
Hope this helps.