Iframe Question [Basic]

I've an iframe in Edge working as intended I'm trying to get rid of the white flash when it loads with this:

style="visibility:hidden;"onload="this.style.visibility = 'visible';"

I believe the reason why this isn't working is because of the end part ... = 'visible'; it has 2 '

so I think thats breaking my existing code so how to I place that code into the code without it breaking....

Heres the existing code:

var container = sym.$('#Stage_Iframe');

var Code = ' <iframe width="100%" height="100%" frameborder="0" scrolling="no" src="Cavas2.html"></iframe>'

container.html(Code);