Accessing hidden field value in javascript

Question

I have a hidden field in my form, I'm setting the hidden field's value on the server and trying to access this value from javascript,

I get the error: Unable to get value of the property 'value': object is null or undefined

If I view the source the hidden field value is set and the ID of the hidden field is the same as the ID I'm calling.

ASPX

            var v = document.getElementById('hxValue').value;
            <asp:HiddenField ID="hxValue" runat="server"/>

VB

            hxValue.Value = "Value1"

I recall doing this before and it should be relatively simple but for some reason, i'm not getting it right.

Answer 1

Your code will work. For simple forms, just add

<asp:HiddenField ClientIDMode="static" ID="hxValue" runat="server"/>

OR

you need to find the client id using

'<%=hxValue.ClientID%>'