Range validation to allow value between negative number (-1) and postive number(+1) in ASP.Net TextBox

I want to put validation in a Textbox, that the numbers entered inside textbox should be between 1 to -1 only i.e., (-1, -0.1, -0.2, -0.3, -0.4, -0.5, -0.6, -0.7 ....... 1 ) I tried below code but "RangeValidator" is not working as per requirement:

HTML:

<asp:RangeValidator ID="RangeValidator1" runat="server" MaximumValue="1" MinimumValue="-1" Text="value between 1 to -1" ErrorMessage="value between 1 to -1" ControlToValidate="TxtY" ValidationGroup="usrvalid"></asp:RangeValidator>
<asp:TextBox ID="TxtY" Text='<%#Eval("Y") %>' runat="server" Width="30%"></asp:TextBox>
<cc1:FilteredTextBoxExtender ID="FilteredTextBoxExtender5" TargetControlID="TxtY" FilterType="Custom" ValidChars="-01234567890." runat="server"></cc1:FilteredTextBoxExtender>

Please reply how to achieve it.