To achieve image transparency with hover, place the following
code into the <img> tag of your code:

Style 1:

style="-moz-opacity:0.4;filter:alpha(opacity=40)"
onmouseover="this.style.MozOpacity=1;this.filters.alpha.opacity=100"
onmouseout="this.style.MozOpacity=0.4;this.filters.alpha.opacity=40"


Style 2:

style="-moz-opacity:1;filter:alpha(opacity=100)"
onmouseover="this.style.MozOpacity=0.4;this.filters.alpha.opacity=40"
onmouseout="this.style.MozOpacity=1;this.filters.alpha.opacity=100"