Numeric validation on TextBox

For any javascript validation I have to add java script event in text box on page load event in asp.net page ,Here I am adding OnKeyPress event on textbox as I am restricting all other key apart from numeric as in below code.

txtAmount.Attributes.Add("onKeypress", " NumericValidation (event);");

Now Below is the HTML code where I will call Numeric Validation function on keypress of Text Box.

 

<asp:TextBox ID="TxtEdpFeb" runat="Server" Text=”” onKeypress="NumericValidation(event)" />

Now below is the javascript function which will call on key press event of Text Box.

function NumericValidation(event) {         if (event.keyCode < 44 || event.keyCode > 57 || event.keyCode == 44 || event.keyCode == 45 || event.keyCode == 46 || event.keyCode == 47)             event.returnValue = false;     }