function elemOn(elem_id){
		if(document.getElementById(elem_id))
			document.getElementById(elem_id).style.display = "block";
	}
function elemOff(elem_id){
		if(document.getElementById(elem_id))
			document.getElementById(elem_id).style.display = "none";
	}
function hideAll(){
		for( var i = 1; i <= 9; i++ )
			elemOff( 'div'+i );
	}
function showOne(elem_id){
		hideAll( );
		elemOn( elem_id );
	}

function changecss(theClass,element,value) {
	//documentation for this script at http://www.shawnolson.net/a/503/
	 var cssRules;
	 if (document.all) {
	  cssRules = 'rules';
	 }
	 else if (document.getElementById) {
	  cssRules = 'cssRules';
	 }
	 for (var S = 0; S < document.styleSheets.length; S++){
	  for (var R = 0; R < document.styleSheets[S][cssRules].length; R++) {
	   if (document.styleSheets[S][cssRules][R].selectorText == theClass) {
	    document.styleSheets[S][cssRules][R].style[element] = value;
	   }
	  }
	 }	
	}