JS 实现搜索功能

HTML代码：

  <div class="search right">
            <form id="form1" action="https://www.sogou.com/web" method="post">
                <input id="key" type="text" name="query" value="请输入关键字"  onfocus="keyFocus()" onblur="keyBlur()"/>&nbsp;&nbsp;
                <input type="button" value="搜索" onclick="submitForm();" />
            </form>
        </div>

JS代码：

        function submitForm() {
            document.getElementById("form1").submit();
        }
        
        function keyFocus() {
            var val = document.getElementById("key").value;
            if(val == "请输入关键字"){
                document.getElementById("key").value = "";
            }
        }
        function keyBlur() {
            var val = document.getElementById("key").value;
            if(val.length <=0){
                document.getElementById("key").value = "请输入关键字"
            }
        }