If the charts are generated on your desktop, say as part of a trading/charting platform, you'll have to save the image to your hard drive and upload to a web site like sylvestor80 did, then link to your post.
If the images are kept on the web & sent to your desktop, (ala Stockcharts) you should be able to link directly.
For those interested, I'm also able to directly link from BigCharts
Jim