How to assign value to id?

Question

I have one string name as id in my .aspx.cs page and one javaScript function SetValue(val) on .aspx page in which I have to assign val to that id. How will I do this in java script fuction SetVal(val)?

Answer 1

If I've understood you correctly, I would have thought that you would need something like the following

function SetValue(elem, val) {
        elem.value = val;
}

and then use like so

var element = document.getElementById('id_of_element');
SetValue(element, 'Value to Set');

EDIT:

if you wanted to make the SetValue function specific to only setting the value of one element (which I wouldn't really recommend - it would be better to write a generic function rather than tie the function to one specific element), you could do the following

function SetValue(val) {
    var elem = document.getElementById('id_of_element');
    elem.value = val;
}

Answer 2

Implement a protected class variable in your .aspx.cs-file and reference that variable - inside your JavaScript function - in your .aspx-file:

.aspx.cs:

public partial class X : System.Web.UI.Page
{
    protected String useMeInJavaScript = "";
}

.aspx:

<script>

SetValue(<%= useMeInJavaScript %>)

</script>

Note: this is pretty simplified, but I'm sure you get the point.