Javascrip倒计数文本框演示
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<title>No.Javascrip倒计数文本框演示</title>
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<SCRIPT LANGUAGE="JavaScript">
<!--
var maxLen=500;
function checkMaxInput(obj)
{
if(obj.value.length>maxLen)
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obj.value=obj.value.substring(0,maxLen);
remLen.innerText="你输入的内容超出了字数限制";
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//-->
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<body>
<table border="1" width="100%" cellspacing="0" cellpadding="0" bordercolorlight="#000" bgcolor="#808080" height="0">
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<td width="50%"><b><font color="#fff">倒计数文本框</font></b></td>
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<tr>
<td width="50%" height="110">
<form name="tickform">
<p align="center">
<textarea name="msgbox" rows="5" cols="31" onKeyDown="checkMaxInput(this)" onKeyUp="checkMaxInput(this)" style="background-color:#000;color:#fff;overflow:auto"></textarea>
</p>
</form>
</td>
</tr>
<tr>
<td width="50%">
<font align="right" id="remLen"><b></b></font></td>
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</table>
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