Thank You Very much for your Reply
Here is my code thats Works perfectly
#region TextBox Email Validation
public class EmailTextBox : System.Web.UI.WebControls.TextBox
{
private System.Web.UI.WebControls.RegularExpressionValidator reg;
public string InvalidMessage;
public string ClientScript="true";
protected override void OnInit(EventArgs e)
{
reg = new System.Web.UI.WebControls.RegularExpressionValidator();
reg.ControlToValidate = this.ID;
reg.ErrorMessage = this.InvalidMessage;
reg.EnableClientScript = (this.ClientScript.ToLower()!="false");
reg.ValidationExpression = @"[^ ]...@[^ ]+\.[^ ]+";
Controls.Add(reg);
}
protected override void Render(HtmlTextWriter w)
{
base.Render(w);
reg.RenderControl(w);
}
}
#endregion
