Can’t enter in form fields in IE6

I know that IE6 is largely redundant and I have forgotten most of the quirks that IE6 and previous threw up.

But I don’t remember this one.

I have a html page with a form linked to a php processing file and I cannot enter anything in the textfield in IE6.

Works fine in all modern browsers, but although the cursor changes to the text entry cursor, it won’t transfer focus?

Can anyone remember why this is happening and how I can make it accept entries through IE6?

Also in #PHP _↴