Question

Hello I am trying to read a textbox(runatserver) after is gets populated form the server into a javascript variable,but it gives me a console error that “can’t read form NULL” however the text box is populated by the string I want to read

this is my text box:

 <form runat="server">

        <asp:TextBox ID="ServerSideTextBox" runat="server" />
    </form>

This is how I am populating it in C#:

ServerSideTextBox.Text= Object_JSON_Class.JSON_DataTable(dt);

it gets the right data also shows the right data string but the PROBLEM is when I try to read the value of the text box like this:

 var oServerSideTextBox= document.getElementById("ServerSideTextBox"); 
var oServerJSON_String=eval("("+oServerSideTextBox.value+")"); 

I get a console error that I can’t read form NULL,but the text box does have the string I want to read into javascript variable,please help

Answer 1

 var txtToIncr = document.getElementById('<%=ServerSideTextBox.ClientID%>')

Check out this link, about reading ASP.Net controls through javascript