<input id="text" type="text">
<script>
var oTxt = document.getlementById(text)
oTxt.onchange = function(){
}
</script>
<input id="text" type="text">
<script>
var oTxt = document.getlementById(text)
oTxt.onchange = function(){
}
</script>
text加引号
var oTxt = document.getlementById("text“);//text加引号
oTxt.onchange = function(){
}