-ms-filter:progid:DXImageTransform.Microsoft.gradient(startColorstr=#7f000000,endColorstr=#7f000000);

filter:progid:DXImageTransform.Microsoft.gradient(startColorstr=#7f000000,endColorstr=#7f000000);

rgba透明值	IEfilter值
0.1	19
0.2	33
0.3	4C
0.4	66
0.5	7F
0.6	99
0.7	B2
0.8	C8
0.9	E5