Input box plus special symbols (forward and backward slashes) checking on input form

<p>图片名称：</p><input type="text" name="afterName"  style="height: 30px;width: 300px;" oninput="changed()"/>

<script type="text/javascript">
function changed(){
    var name = $("input[name='afterName']").val();    
    var tar=new RegExp(".*[/\\\\].*");
    if(name == ""){
        return;
    }
    if (tar.test(name)) {
        alert ("请不要输入特殊字符!");
        $("input[name='afterName']").val("");
        }
}
</script>

 

Image Name: