js行背景变色、显示提示层的代码

//保存为一个js文件，引入使用就行了

function showHelp(id) {
    var obj = document.getElementById(id);
    obj.style.display = "";
    obj.style.left = event.x;
    obj.style.top = event.y;
}
function hideHelp(id) {
    var obj = document.getElementById(id);
    obj.style.display = "none";
}
//<div id="tooltip1" style="position:absolute;display:none; z-index: 1000; border: solid 1px black;padding: 10px; background: white;">提示</div>
// onmouseover="showHelp('tooltip1');" onmouseout="hideHelp('tooltip1');" 
var c;
function cc(obj) {
    c = obj.style.backgroundColor;
    obj.style.backgroundColor = '#E7EDFE'

}
function cc1(obj) {
    obj.style.backgroundColor = c;
}
// onmouseover="cc(this)" onmouseout="cc1(this)"