function getCssStyle(filename,stylename) {
   rules=getCssRules(filename);
   if (rules) {
       style=getCssStyleFromRule(rules,stylename);
       if (style) {
           return style
       }
   }
   return null;
}

function getCssRules(filename) {
   var n=filename.length+1;
   for (var i = 0; i < document.styleSheets.length; i++ ) {
       var file=document.styleSheets[i].href;
       if (file.substr(file.length-n,n)=='/'+filename) {
           if (document.styleSheets[i].cssRules) return document.styleSheets[i].cssRules;
           if (document.styleSheets[i].rules) return document.styleSheets[i].rules;
           return null;
       }
   }
   return null;
}

function getCssStyleFromRule(rules,stylename) {
   var n=stylename.length+1;
   for (var i = 0; i < rules.length; i++ ) {
       if (rules[i].selectorText==stylename) {
           return rules[i].style;
       }
   }
   return null;
}

function ColorToString(color) {
   if (color.substring(0,1)=='#') return color.substr(1);
   if (color.substring(0,4)=='rgb(') {
       m=color.match(/\(\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d+)\s*\)/);
       return parseInt(m[1]).toString(16)+parseInt(m[2]).toString(16)+parseInt(m[3]).toString(16);
   }
   return color;
}