Imported mp4 file not showing on export

Can someone help, please, as I must have had the stupid pill this morning.

Drag and drop mp4 file into WDP12 which creates the following HTML code:

<video class="xar_meplayer" src="index_htm_files/introduction.mp4" controls autoplay width = "100%" height="100%"/>

but the video does not appear in either preview mode or export.

What am I doing wrong?

Many thanks.

It probably ended up on the MouseOver or background layer.

That was it - moved from MouseOver to MouseOff and video appears.

Many thanks for your help!

Kind regards,
Geoffrey

:)