How to Stop ValidationExpression on Clearing The Text Box

Question

Using an ASP.NET application I have a Textbox as:

<asp:TextBox ID="NEEDID" runat="server" MaxLength="50" ></asp:TextBox></div>
<asp:RegularExpressionValidator ID="AdvNeedIdValidator" runat="server"
ControlToValidate="NEEDID" ErrorMessage="Need ID is numeric."
ForeColor="Red" ValidationExpression="^\d*\.?\d*$">*</asp:RegularExpressionValidator> 

and two buttons for Search and Clear Search for c;earing search box.

<asp:Button ID="Adv_SearchButton" runat="server" Text="Search" ClientIDMode="Static" OnClick="Adv_SearchButton_Click"/> 

<asp:Button ID="ClearFilterButton" ClientIDMode="Static" CssClass="thin-button" runat="server" Text="Clear Search" onclick="ClearFilterButton_Click" />

now my problem is even on clearing the search box the ValidationExpression is functioning! while it is suppose to only run when the Search button clicks! Can you please let me know how to fix this?

Thanks

Answer 1

Add the attribute CausesValidation="false" to your clear button. Since your button causes a postback, it is going to validate the content of the TextBox .

Better still, consider using Javascript to clear the content of the TextBox to improve the user experience by avoiding the postback to your server.