when i click on a text-field in my html-file, I want to open another HTML-document in a new window, so I use

[JSCRIPT]
window.open('MyForm.htm','', 'width=800, height=700, status=no, toolbar=no, menubar=no, scrollbars=yes');
[/JSCRIPT]

Problem : it doesn't open !!

Is there something in XP(professional ed) that blocks this line ?
'cause i already tried it on XP Embedded, and it worked just fine !