Websforms want jQuery confirm after button clicked

Hi

I have a web form that a user is entering hours worked. When the user presses the button

<asp:Button ID="cmdSubmit" CausesValidation="true" runat="server" Text="Submit Hours" OnClick="cmdSubmit_Click" />

I would like a jQuery box to ask if the hours that have been tallied and put in this put in this textbox

<asp:TextBox ID="TotalHours"  CssClass="data-input"  ClientIDMode="Static" runat="server" />

to appear and ask if the value in this textbox are correct.  If the user chooses "Yes" I want the dialogbox to go on and execute the event at

OnClick="cmdSubmit_Click"
 
 if not I want the event to not happen