c# - set value in text box not more than 2 decimal places -

i have 1 text box allow user key in value decimal value.how set in text box can enter 2 decimal places. now, user can key in more 2 decimal places. below code text box:

<td><b>payment amount:</b></td>                             <td colspan="2">                                 <asp:textbox id="txtpayment" runat="server" enabled="true" cssclass="form-control"/>                                 <asp:requiredfieldvalidator id="rfvpayment" runat="server" controltovalidate="txtpayment" validationgroup="submitgroup" display="dynamic" errormessage="* please fill in section" />                                 <asp:rangevalidator id="rgpayment" runat="server" controltovalidate="txtpayment" display="dynamic" type="double"/>                             </td> 

for text box, on id=rgpayment, use rangevalidator validate value. here code:

protected void lnkbtnb2cproceed_click(object sender, eventargs e)     {         rgpayment.maximumvalue = "30000";         rgpayment.minimumvalue = "1";         txtpayvia.text = "retail banking";         if (checkamount())         {             proceed(resources.default.fpxmsgtokenb2c);             trsupportedchannel.visible = false;         }     }      protected void lnkbtnb2bproceed_click(object sender, eventargs e)     {         rgpayment.maximumvalue = "1000000";         rgpayment.minimumvalue = "2";         txtpayvia.text = "corporate banking (fpx)";         if (checkamount())         {             proceed(resources.default.fpxmsgtokenb2b);             trsupportedchannel.visible = false;         }     } 

thank you

you can download jquery numeric mask plugin , add it's reference on page. use

$('[id*="txtpayment"]').numeric({ decimal : ".",  negative : false, scale: 2 });