textarea 控制输入字符字节数(示例代码)

按字符数控制：
复制代码 代码如下:
             onkeyup="if(this.value.length>2000) this.value=this.value.substr(0,2000)"<BR>             onkeydown="if(this.value.length>2000) this.value=this.value.substr(0,2000)"<BR>             onblur="if(this.value.length>2000) this.value=this.value.substr(0,2000)"<BR>             onpropertychange= "if(this.value.length>2000) this.value=this.value.substr(0,2000)">

按字节数控制：
复制代码 代码如下:
      onkeydown="key1=this.value;value1 = key1.replace(/[u4e00-u9fa5]/g,' ');if(value1.length>500) this.value=this.value.substr(0,500)" <BR>      onkeyup="key1=this.value;value1 = key1.replace(/[u4e00-u9fa5]/g,' ');if(value1.length>500) this.value=this.value.substr(0,500)"<BR>      onblur="key1=this.value;value1 = key1.replace(/[u4e00-u9fa5]/g,' ');if(value1.length>500) this.value=this.value.substr(0,500)"  <BR>      onchange="key1=this.value;value1 = key1.replace(/[u4e00-u9fa5]/g,' ');if(value1.length>500) this.value=this.value.substr(0,500)">