gistfile1.txt

.rgba(@colour, @alpha) {
    @alphaColour: hsla(hue(@colour), saturation(@colour), lightness(@colour), @alpha);
    @ieAlphaColour: argb(@alphaColour);  

    background-color: @colour; // Fallback for older browsers 
     
    // IE hacks
    zoom: 1; // hasLayout
    background-color: transparent\9;
    -ms-filter:  "progid:DXImageTransform.Microsoft.gradient(startColorstr=@{ieAlphaColour}, endColorstr=@{ieAlphaColour})"; // IE 8+
        filter: ~"progid:DXImageTransform.Microsoft.gradient(startColorstr=@{ieAlphaColour}, endColorstr=@{ieAlphaColour})"; // IE 6 & 7

    background-color: @alphaColour; 
 
}