Best to also scale the image by including a width= parameter in the HTML. 300 pixels is good for a smaller image, 400 or 500 for an average size, and 600 if there's lots of detail needing to be seen. Larger images may cause the right hand display margin to be way off to the right making reading of the entire thread difficult by constantly having to scroll to the right. I once suggested that Jarrod make the default image width 400 pixels to help keep Expanded Thread displays readable, but that didn't happen.

<img src="url" width=400>

The url only needs to be surrounded in double quotes if it contains a space character, otherwise the double quotes are optional.

It's usually simplest and safest to use copy and paste functions to insert the web link of the image from a browser display of the image and then insert it while typing the double quotes.
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now