How to get the value from span element inside div that are set from C# code using Javascript

Question

I have an aspx file with span sections inside a div:

 <div id="child1container" runat="server">
    <span class="textclass" id="UserName" runat="server" ClientId="username1"></span>
    <span class="textclass" id="BankName" runat="server" ClientId="bankname"></span>
 <div>

Here the values for Username and Bankname are set by the code behind (using .cs file). Once after the value is being set by the code, I need to capture the value of username and bankname in javascript using document.getElementById.value. Could someone help me on how to get this value in javascript so that I can do some more manipulation after this. I know I need to use window.onload function, but would like to know how to get the value from span element.

Answer 1

Typically ASP.NET controls have a ClientID property. That is how the ID will render in HTML.

<span class="textclass" id="BankName" runat="server" ClientId="bankname"></span>

Then in your javascript:

document.getElementById('<%= BankName.ClientID %>')

Answer 2

var val = document.getElementById（“ <％= BankName.ClientID％>”）。value