disable page controls until page is fully loaded

 hi experts
my page currently have lytebox which previews the picures and datalist which populate from a DB retrieveing from BLOB datatype and spiting a preview image onto the datalist
as i know this takes roughly 5-X secs depending on the size of the BLOB file

problem:
when some BLOB files are small it takes little time to retrieve, but because the page isn't fully loaded... the datalist still has stuff to populate with
the lytebox doesn't work at all as it requires the page to be fully loaded, so when uses click on the link to preview the small images when page isn't fully loaded, it crashes

question:
how can i disable the page until the page is fully loaded?
i'm after some animiation while page is loading...

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