Try this code:
UI:
<asp:LinkButton ID="LinkButton1" runat="server" Font-Bold="True"
Font-Underline="False" onclick="LinkButton1_Click">one</asp:LinkButton><br />
<asp:LinkButton ID="LinkButton2" runat="server" Font-Bold="True"
Font-Underline="False" onclick="LinkButton2_Click">two</asp:LinkButton><br />
<asp:LinkButton ID="LinkButton3" runat="server" Font-Bold="True"
Font-Underline="False" onclick="LinkButton3_Click">three</asp:LinkButton><br />
<asp:LinkButton ID="LinkButton4" runat="server" Font-Bold="True"
Font-Underline="False" onclick="LinkButton4_Click">four</asp:LinkButton><br />
C# code:
protected void LinkButton1_Click(object sender, EventArgs e)
{
LinkButton1.Enabled = false;
LinkButton2.Enabled = true;
LinkButton3.Enabled = true;
LinkButton4.Enabled = true;
LinkButton1.BackColor = System.Drawing.Color.Gray;
}
protected void LinkButton2_Click(object sender, EventArgs e)
{
LinkButton2.Enabled = false;
LinkButton1.Enabled = true;
LinkButton3.Enabled = true;
LinkButton4.Enabled = true;
LinkButton2.BackColor = System.Drawing.Color.Gray;
}
protected void LinkButton3_Click(object sender, EventArgs e)
{
LinkButton3.Enabled = false;
LinkButton1.Enabled = true;
LinkButton2.Enabled = true;
LinkButton4.Enabled = true;
LinkButton3.BackColor = System.Drawing.Color.Gray;
}
protected void LinkButton4_Click(object sender, EventArgs e)
{
LinkButton4.Enabled = false;
LinkButton1.Enabled = true;
LinkButton3.Enabled = true;
LinkButton2.Enabled = true;
LinkButton1.BackColor = System.Drawing.Color.Gray;
}