How to restrict user from selecting date which is already selected

Hi,

You need to write below code on calendar2_SelectedEvent 

if(calendar1.selecteddate.value == calendar2.selecteddate.value)

{

Response.Write("<script>window.alert('End date not equal to start date')</script>");

txtenddate.focus();

return;

}

Please try with this one...

Use compare validator

 Date 1<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
        Date 2<asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
        <asp:CompareValidator ID="CompareValidator1" Operator = "NotEqual" Type = "Date" ControlToValidate = "TextBox1" ControlToCompare = "TextBox2" runat="server" ErrorMessage="Date1 should be different from Date2"></asp:CompareValidator>
        <asp:Button ID="Button1" runat="server" Text="Validate" />

Hi,,

Yes,You may use CompareValidator control for this purpose

I also have to give user the option if he does not want to specify the end date it should be left empty

suchitra says:I also have to give user the option if he does not want to specify the end date it should be left empty

Have you even tried what I gave. It allows empty inputs. It only compares when you have both textboxes filled