If this is online, then your iframe paths will not work:
That refers to your hard drive on your own computer. The image error may be because you have an incorrect relationship between where the image is and the page using it. Plus, you may have forgot to upload the image. Do not close the image tag unless you are coding to XHTML. Even then you'll be flagged for no alt="" attribute and no character set tag.
<iframe src="C:\Users\Graham\Desktop\WebPage\SCROLLINGCONTENT1.html" width="1081" height="500" scrolling="yes">
Why Validate?: http://validator.w3.org/docs/why.html
CSS Validator: http://jigsaw.w3.org/css-validator/
HTML Validator: http://validator.w3.org/#validate_by_uri+with_options