LESS opacity function

opacity.less

/*

description - a cross browser opactity function

usage example:
.my-class{
    .opacity(.50);
}

@param: amount - expects a floating point decimal. 

 */
.opacity(@amount){
    @whole-number-amount : @amount * 10; //convert from decimal to whole    
    zoom:1; 
    -ms-filter:"progid:DXImageTransform.Microsoft.Alpha(Opacity=@{whole-number-amount})";
    filter: alpha(opacity=@whole-number-amount);
    -moz-opacity:@amount;
    -khtml-opacity: @amount;
    opacity: @amount;
}