Focus lost when tapping & change title value insides a window

<zk>
<label multiline="true">
Focus lost when tapping & change title value insides a window . (only firefox does well, chrom and IE all has issue.)
1. in Chrome, edit textbox1 and tab, it should focus on textbox2 and select all of textbox2 and the window title should change to the value you editied.
2. in IE9, edit textbox1 and tab, it should focus on textbox2 and select all of textbox2 and the window title should change to the value you editied.
  
</label>
	<zscript>
	
	</zscript>
	<window id="win" title="no title" border="normal">
		<vlayout>
			<label id="lb" value="no value"/>
			<textbox id="tb1" onChange='win.title = self.value' value="Title 1"/>
			<textbox id="tb2" onChange='lb.value = self.value' value="Label 1"/>
			<textbox id="tb3" onChange='win.title = self.value' value="Title 3"/>
		</vlayout>
	</window>
</zk>