problema com switch case

<script language="javascript" type="text/javascript">

var mywindow;

function setnull()

if (mywindow != null)
	{
 if(mywindow.closed == true)
 {
 mywindow=null;

 }
	}

}

function openw()

 var element = document.getElementById("hdServerHour").value;
 hour_txt = parseInt(element);
 contryName = '<%=me.CountryName %>'
 //hour_txt = 10;
 // Here is the If that validate hour
 switch (contryName) {
 case "GC AMS" :
 if (hour_txt >= 12 && hour_txt <= 21)
 {
 if ( mywindow ==null )
 {
 mywindow=window.open('http://usmesa0050/WebAPISamples761/CondorChat/HtmlChatFrameSet.jsp?username=<%=Me.data.FirstName %>&lastname=<%=Me.data.LastName %>&email=<%=Me.data.Email %>&subject=<%=me.subject%>&language1=<%=me.language %>&display1=<%=me.CountryName %>','mywindow','menubar=0,resizable=0,left=420,top=200,width=394,height=505,scrollbars=0');
 window.close()
 }
 }
 else if ( mywindow ==null )
 {
 mywindow=window.open('http://usmesa0050/WebAPISamples761/CondorChat/HtmlChatFrameSet.jsp?username=<%=Me.data.FirstName %>&lastname=<%=Me.data.LastName %>&email=<%=Me.data.Email %>&subject=<%=me.subject%>&language1=<%=me.language %>&display1=<%=me.CountryName %>','mywindow','menubar=0,resizable=0,left=420,top=200,width=394,height=505,scrollbars=0');
 window.close()
 }
 else
 {
 //window.location="//Chat/Unavailable.apsx";
 alert('The Chat session is only available from 11h to 21h GMT!');
 }

 break;
 case "AUSTRAL":
 if (hour_txt >= 2 && hour_txt <= 21)
 {
 if ( mywindow ==null )
 {
 mywindow=window.open('http://usmesa0050/WebAPISamples761/CondorChat/HtmlChatFrameSet.jsp?username=<%=Me.data.FirstName %>&lastname=<%=Me.data.LastName %>&email=<%=Me.data.Email %>&subject=<%=me.subject%>&language1=<%=me.language %>&display1=<%=me.CountryName %>','mywindow','menubar=0,resizable=0,left=420,top=200,width=394,height=505,scrollbars=0');
 window.close()
 }
 }
 else if ( mywindow ==null )
 {
 mywindow=window.open('http://usmesa0050/WebAPISamples761/CondorChat/HtmlChatFrameSet.jsp?username=<%=Me.data.FirstName %>&lastname=<%=Me.data.LastName %>&email=<%=Me.data.Email %>&subject=<%=me.subject%>&language1=<%=me.language %>&display1=<%=me.CountryName %>','mywindow','menubar=0,resizable=0,left=420,top=200,width=394,height=505,scrollbars=0');
 window.close()
 }
 else
 {
 //window.location="//Chat/Unavailable.apsx";
 alert('The Chat session is only available from 11h to 21h GMT!');
 }

 break;
}
}
</script>

Alguem tem idéia de por que não funciona.

Bem..

Funcionar funciona.

mas ele num trava quando passa do horario.. .

ele executa mesmo assim.

mesmo quando passa e quando é antes do horario.