Request.Form "Collection is only readonly" when trying to set text box content
<p>Saving the values in the Lists &amp; works fine.</p>

<pre><code> abc= (ABC)(Session["xml"]);

        string ctrlStr = String.Empty;
        foreach (string ctl in Page.Request.Form)
        {
            if (ctl.Contains("something"))
            {
                ctrlStr = ctl.ToString();
                abc.student[0].marks[j].science.something.Value = Convert.ToDecimal(Request.Form[ctrlStr]);
            }
</code></pre>

<p>Want to retrieve the values from the saved object when I click on edit button back on the respective dynamic textboxes....</p>

<pre><code> foreach (string ctl in Page.Request.Form)
        {
            if (ctl.Contains("studentname"))
            {
                ctrlStr = ctl.ToString();
                (Request.Form[ctrlStr]) = abc.student[0].marks[x].science.studentname.ToString();---Gives an error stating the collection is only readonly
            }
        }
</code></pre>
