function onchange_upload_text( upload )
    {
    var val= upload.value;

    var res;

    if  ( val == "" )
	{ return true;	}

    res= val.match( /^(.*\.doc|.*\.rtf|.*\.txt|.*\.pdf|.*\.html)$/ );
    if  ( ! res )
	{
	alert( "*.doc;*.rtf;*.txt;*.pdf;*.html" );
	upload.focus(); upload.select();
	return false;
	}

    return true;
    }