public/ckeditor/_source/core/dom/element.js
function( opacity )
		{
			if ( CKEDITOR.env.ie )
			{
				opacity = Math.round( opacity * 100 );
				this.setStyle( 'filter', opacity >= 100 ? '' : 'progid:DXImageTransform.Microsoft.Alpha(opacity=' + opacity + ')' );
			}
			else
				this.setStyle( 'opacity', opacity );
		}
function( opacity )
		{
			if ( CKEDITOR.env.ie )
			{
				opacity = Math.round( opacity * 100 );
				this.setStyle( 'filter', opacity >= 100 ? '' : 'progid:DXImageTransform.Microsoft.Alpha(opacity=' + opacity + ')' );
			}
			else
				this.setStyle( 'opacity', opacity );
		}
function ( opacity ) { if ( CKEDITOR . env . ie ) { opacity = Math . round ( opacity * 100 ) ; this . setStyle ( 'filter' , opacity >= 100 ? '' : 'progid:DXImageTransform.Microsoft.Alpha(opacity=' + opacity + ')' ) ; } else this . setStyle ( 'opacity' , opacity ) ; }
Sets the opacity of an element.
@param {Number} opacity A number within the range [0.0, 1.0].
@example
var element = CKEDITOR.dom.element.getById( 'myElement' );
<b>element.setOpacity( 0.75 )</b>;
Sets the opacity of an element .