I am looking for some alternate way to do:
When I do the W3C validation, I am getting the error:
There is no HTML attribute named transparency, so you will always get an error with iframe transparency=true
if you set opacity to zero, you won't see the element at all - you need to define the degree of opacity:
opacity: 0.25; /* all modern browsers */
filter: alpha(opacity=25) /* IE */
The above CSS (note: opacity values are 0-100 for IE, 0-1 for other browsers) will allow other elements behind (e.g. a page background image) to show through, even if the element with the opacity setting has a coloured background.
For more control over transparency, see RGBA (A = alpha), but watch out for variable browser support.