document.form[0] is Null or Not an Object error when hiding a text field in ASP.Net
<p>I am hiding a TextBoxin my aspx page like this:</p>

<p><em>myField.visible=false;</em></p>

<p>Now I have a DropDown as well which tries to access the TextBox on IndexChange. The problem is, it cant access the hiffen TextBox and I am getting <strong>document.form[0] is Null or Not an Object</strong>. How can I solve that? Is the some check for that in JavaScript?</p>

<p>Thanks :-)</p>
