function editCats ( evt ) { if (document.getElementById) { mX = evt.clientX +150; mY = evt.clientY + 150; } else { mX = evt.pageX +150; mY = evt.pageY + 150; } var MyPosition = 'scrollbars=no,toolbar=no,left=' + mX + ',top=' + mY + ',screenx=' + mX + ',screeny=' + mY; var cat_ids = document.selectcategory.elements['cat_id'].value; url = "catsel.php?form=selectcategory&cats=" + cat_ids; var catWindow = window.open (url,"EditCat","width=385,height=250," + MyPosition); }