js 显示输入框输入的内容

JS:
<mce:script language="javascript" type="text/javascript"><!--
function regInput(obj, reg, inputStr) {
var docSel = document.selection.createRange()
if (docSel.parentElement().tagName != "INPUT") return false
oSel = docSel.duplicate()
oSel.text = ""
var srcRange = obj.createTextRange()
oSel.setEndPoint("StartToStart", srcRange)
var str = oSel.text + inputStr + srcRange.text.substr(oSel.text.length)
return reg.test(str)
}
// --></mce:script>