1. .cantUse { 
    2.   -webkit-filter: grayscale(100%); 
    3.   -moz-filter: grayscale(100%); 
    4.   -ms-filter: grayscale(100%); 
    5.   -o-filter: grayscale(100%); 
    6.   filter: grayscale(100%); 
    7.   filter: gray; 
    8. }