var theme = "";
		  
	function setStyleSheet(theme1, theme2) {
		if (theme != theme2){
			theme = theme2;
		} else {
			theme = theme1;
		}
        for ( i = 0; i < document.styleSheets.length; i++ ) {
        	if ( document.styleSheets[i].title ) {
        		document.styleSheets[i].disabled = true;
        		if ( document.styleSheets[i].title == theme )
       			 document.styleSheets[i].disabled = false;
      		}
   		}
   	}