Im trying to embed this code from vidello but its not sitting in my blog as anything but a straight thin line ! ive removed the text upto <iframe but it just puts it at the top of the frame . im not someone whos great with code so any help appreciated.
Hi @xmelaniex 
iframes, and or absolute positioned elements, need a defined height:
style=“position:absolute;top:0;left:0;width:100%;height:100%;border:none;”
should be:
style=“position:absolute;top:0;left:0;width:100%;height:300px; border:none;”
Also see this for other approaches
https://stackoverflow.com/questions/325273/make-iframe-to-fit-100-of-containers-remaining-height
Keeping in mind that will be the height on all device types.
Well made services should have additional info on how to properly integrate there service.
If you need this customized then contact me for services
Contact info in forum signature.
ALWAYS please provide context, examples: store url, theme name, post url(s) , or any further detail in ALL correspondence.
Good Luck.