Validation control preventing button from redirecting to another page

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C#

Hi i am doing a login page and i have used validation controls for username textbox and password textbox.Along with this, i have created image button which direct to another page.but when i click on that image button, this validation control prevents me from going to that page.Can anyone tell me how to avoid that.Below is my html code:

 <asp:ScriptManager ID="ScriptManager1" runat="server">
    </asp:ScriptManager>
    <asp:UpdatePanel ID="UpdatePanel1" runat="server">
    <ContentTemplate>
     UserName/Email:<br />
<asp:TextBox ID="TextBox1" runat="server" MaxLength="60" class="water"   ></asp:TextBox><asp:RequiredFieldValidator
    ID="RequiredFieldValidator1" runat="server" ErrorMessage="*Username/Email Required" 
            ControlToValidate="TextBox1" ForeColor="Red"></asp:RequiredFieldValidator><br />
Password:<br />
<asp:TextBox ID="TextBox2" runat="server" MaxLength="60" class="water"  TextMode="Password" ></asp:TextBox><asp:RequiredFieldValidator
    ID="RequiredFieldValidator2" runat="server" ErrorMessage="*Password Required" 
            ControlToValidate="TextBox2" ForeColor="Red"></asp:RequiredFieldValidator><br />
            <asp:Button ID="Button7" runat="server" Text="Login" BackColor="#BD362F" 
          ForeColor="White" onclick="Button7_Click"></asp:Button><br />
                  <asp:ImageButton ID="ImageButton1" runat="server" 
            ImageUrl="~/images/new_user_signup.jpg" Width="150px" 
    onclick="ImageButton1_Click" />
    
    </ContentTemplate>
    </asp:UpdatePanel>