try this
html:
css script:
div {
width: 200px;
height: 200px;
background-color: #eee;
border: 1px solid black;
}
.current_active{
background-color: red;
}
jquery:
$("#btnclick").click(function(){
$("#current").toggleClass("current_active");
});
JSFiddle
ps: include the jquery library file