                        课程
                    
                        /前端开发
                        
                            /JavaScript
                        
                        /JavaScript入门篇

为什么加上window.onload=function就是错误的

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
#div1 {width: 200px;height: 200px;background: #e84a7e;}
</style>
<script>
window.onload=function setColor(color)
{
var oDiv=document.getElementById('div1');
oDiv.style.background=color;
}
</script>
</head>
<body>
<input type="button" value="变绿" onclick="setColor('green');">
<input type="button" value="变红" onclick="setColor('red');">
<input type="button" value="变黄" onclick="setColor('yellow');">
<div id="div1"></div>
</body>
</html>