thank you for you reply.
but do help me to understand where did i do wrong on below steps: (please refer attachment, is the steps that i did)
1) click on the url : http://www.fusioncharts.com/Demos/ExportChart/Contents/client_export.html
2) click on the "Export Chart", and it will capture the data.
3) after finish capture the data, a "Save" button will appear along with the file format that you wanted to save into.
4) i click "Save", and the save dialog box prompt with the default file name, "FusionCharts". (note: the name is without any extension as the end of file as i turn ON the "Hide extension" setting on my folder option)
5) then i rename it to "newfile". (note: i also name it without the extension), and i click "Save" button.
6) wala~ the "newfile" become an unknown file format.
since we are refering to the same code program, please guide me, which steps did i do wrong that causing the file become unknown file format after i rename the default file name.
thank you so much , looking for your reply.