Data Controls :: Show GridViewRow Details From GridView Which Is Inside Of UpdatePanel To TextBoxes?

I have Gridview in UpdatePanal but their is problem with template field 

<asp:TemplateField HeaderText="EDIT">
<ItemTemplate>
<asp:LinkButton ID="lnkEdit" runat="server" ToolTip="Edit Unit" OnClick="lnkEdit_Click"
CausesValidation="False"><img src="IMG/screw-driver.png" alt="" /></asp:LinkButton>
</ItemTemplate>
</asp:TemplateField>

and link button click event is 

protected void lnkEdit_Click(object sender, EventArgs e)
{
GridViewRow clickedRow = ((LinkButton)sender).NamingContainer as GridViewRow;
ScriptManager sm = (ScriptManager)Page.Master.FindControl("smanager");
sm.RegisterPostBackControl(clickedRow);
lblUnitID.Text = clickedRow.Cells[0].Text;
txtUnitName.Text = clickedRow.Cells[1].Text;
txtDecimal.Text = clickedRow.Cells[2].Text;
btnUnit.Text = "Update";
}

but text box value is not set but when we do it in  PostBackTrigger is work.

can we do this AsyncPostBackTrigger.