Can not change value in textbox when edit
<p>In the Page-Load method I set value for textbox like this</p>

<pre><code>txtid.Value = pro.getId().ToString();
txtmodel.Text = pro.getModal();
txtname.Text = pro.getName();
cbCategory.SelectedValue = pro.getCategory();
txtprice.Text = pro.getPrice().ToString();
txtDescription.Text = pro.getDescription();
</code></pre>

<p>and when I submit to edit the Product I get value</p>

<pre><code>string id = txtid.Value.ToString();
string modal = txtmodel.Text.ToString();
int category = int.Parse(cbCategory.SelectedValue);
string name = txtname.Text.ToString();
string description = txtDescription.Text.ToString();
</code></pre>

<p>and I try to change value different with the original but when I bug it's still keep original value and save to database.</p>
