Thank you, Rahkonen Jukka. Your advice helps me to fix this problem. I was wrong in identification of EXTENT and layer data. By using "ogrinfo", I fixed it.<br><br>Best regards,<br><br>Tran Tho Ha<br><br><br><br>
<div class="gmail_quote">On Sun, Mar 16, 2008 at 2:57 PM, Rahkonen Jukka <<a href="mailto:Jukka.Rahkonen@mmmtike.fi">Jukka.Rahkonen@mmmtike.fi</a>> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Tran Tho Ha wrote<br>
<div class="Ih2E3d"><br>
> Thanks Frank for your advice.<br>
> I identified that I was using old version of MS4W. So when I upgrade to MS4W<br>
> 2.2.7, it works. At least, the errors I mentioned before didn't occurred<br>
> anymore. But I have another problem: I only get a blank image, instead of a<br>
> map. Can you suggest which things should I check for this error?<br>
<br>
</div>I believe that the most common reason for getting an empty map is simply that<br>
there are no data on the area of the request. Check very first that your<br>
request and mapfile are using the same projection and that the layer data is<br>
having a correct projection, which I believe to be always epsg:4326 for gpx.<br>
Then check that the mapfile extents are correct so that your data fall inside.<br>
I suggest to start with keeping everything in epsg:4326. Use ogrinfo to<br>
see the extents of the data and put those values to mapfile EXTENT and to your<br>
request.<br>
<font color="#888888"><br>
-Jukka Rahkonen-<br>
<br>
</font></blockquote></div><br>