Hello Neeraj,
Try this
In the page load event of this page add the following code
Dim navDiv As HtmlContainerControl = DirectCast(Me.Master.FindControl("divwelcome"), HtmlContainerControl)
navDiv.Visible = False
Or
check the aspx for id and runat= "server"
<div id="divwelcome" runat="server">
All the best:) pls write back for support.