Question

Javascript的onblur和onfocus

<input type="text" name="user" value="请输入..." onblur="if(this.value='')value='请输入...'" onfocus="if(this.value='请输入...')this.value=''">
当鼠标放上去时，请输入消失，鼠标点到别处有出现

Answer 1

按我下面的方法就算是自己打的"请输入..."也不会去掉了..
<script type="text/javascript">
function _02110811onblur(o) {
if (this.value == '') {
this.isAir = true; this.value = '请输入...'
}
}
function _02110811onfocus(o) {
if (this.isAir == true || typeof this.isAir == "undefined") {
this.value = ''; this.isAir = false;
}
}
</script>
<input type="text" value="请输入..." onblur="_02110811onblur.call(this);" onfocus="_02110811onfocus.call(this);" />

Answer 2

<input type="text" name="user" value="请输入..." onblur="if(this.value=='')value='请输入...'" onfocus="if(this.value=='请输入...')this.value=''">

Answer 3

this.value == ''是判断条件,少了个 = 号