> 1) Add 'this.checked' to your function call:

> side_bar_html += '<form name=testform>130 East <INPUT TYPE="checkbox"
> NAME="Item1" VALUE="1"  onClick="myclick(this.checked)"></form>';

> (No need to use 'javascript:' in that onClick handler btw).

> 2) Create your polyline just once - it needs to be created outside of
> any functions so that 'myPolyline' is a global variable and then your
> myclick() function can access it:

> var myPolyline = new GPolyline([new GLatLng(40.110484,-88.227189),new
> GLatLng(40.110418,-88.228386), new GLatLng(40.11012,-88.228865)],
> "#ff0000", 5);

> 3) Update your myclick() function:

> function myclick(state){
>  if(state){
>   // show polyline
>   map.addOverlay(myPolyline);
>  } else {
>   // remove polyline
>   map.removeOverlay(myPolyline);
>  }

> }

> Martin.

> On 6 Nov, 06:29,iwotic<aunah...@gmail.com> wrote:

> > I am a newbie in Google Maps API, I got a question about showing and
> > hiding a polylines. My goal is to click a checkbox, a polyline will
> > show up on the map. I got this part done. However, when I uncheck the
> > box, I want the line to disappear. I am not sure how I can do it.
> > After looking around, it seems like people use removeOverlay()
> > and .hide() function but I couldn't get it to work.

> > Here is how  the checkbox in my code work:
> >  side_bar_html += '<form name=testform>130 East <INPUT TYPE="checkbox"
> > NAME="Item1" VALUE="1"  onClick="javascript:myclick()"></form>';

> > in the myclick(), i have this:
> > var polyline = new GPolyline([new GLatLng(40.110484,-88.227189),new
> > GLatLng(40.110418,-88.228386), new GLatLng(40.11012,-88.228865)],
> > "#ff0000", 5);
> > map.addOverlay(polyline);

> > This is something I want my check and uncheck box to do:http://www.geocodezip.com/GenericMapBrowser.asp?filename=RiverWalk080...

> > Can some one please help me?? What should I do? Thank you!!