Need a simple css code that renders the opacity of an image as a style. Cross browser compatible on Google Chrome, Firefox, IE, Safari

• Step 1 Set the original opacity of the image, ive gone for 90%

.img_opacity { opacity: 0.9; /* works in Chrome 4+, Firefox 2+, Safari 3.1+, Opera 9+, IE9, iOS 3.2+, Android 2.1+ */
filter: alpha(opacity=90); /*works in IE6-IE8 */ }

• Step 2 Set the opacity to change when you hover over the image

.img_opacity:hover{ opacity: 0.7; /* works in Chrome 4+, Firefox 2+, Safari 3.1+, Opera 9+, IE9, iOS 3.2+, Android 2.1+ */
filter: alpha(opacity=70); /* works in IE6-IE8 */ }

Simple,
Heres the full code to just copy and paste

.img_opacity { opacity: 0.9; /* works in Chrome 4+, Firefox 2+, Safari 3.1+, Opera 9+, IE9, iOS 3.2+, Android 2.1+ */
filter: alpha(opacity=90); /*works in IE6-IE8 */ }
.img_opacity:hover{ opacity: 0.7; /* works in Chrome 4+, Firefox 2+, Safari 3.1+, Opera 9+, IE9, iOS 3.2+, Android 2.1+ */
filter: alpha(opacity=70); /* works in IE6-IE8 */ }