What is the use of Post-backUrl property?

Answer:

PostbackUrl property is used to work
with Cross-page posting i.e. to get
previous page values.It's used in Button,
Link-Button,Image-button and so on.

In the postbackurl,we have to supply path of another page hich will be treated as Destination page.

<asp:Button ID="Button1" runat="server" Text="Button" PostBackUrl="~/frm_employee_master.aspx" />

After clicking on Button1,page will redirect to employee master page.