<html> <head> <title>limited textarea</title> <script type="text/javascript"> var TextUtil = new Object(); TextUtil.isNotMax=function(oTextArea)
...{
return oTextArea.value.length !=oTextArea.getAttribute("maxlength");
} //禁止粘贴 onpaste="return false" //select box,HTML DOM为每个<select/>元素定义了options集合，她是控件的所有的 //<option/>元素的列表，要获取,option的显示的文本与值 function testSelect() ...{ var test = document.getElementById("testSelect"); alert(test.options[0].value); alert(test.options[0].getAttribute("value")); alert(test.options[0].firstChild.nodeValue); alert(test.options[0].text); alert(test.options[0].index); alert(test.options[0].selected); test.options[0].firstChild.nodeValue ="zhang xiong"; } //添加 一个option选项． function appendOption() ...{ var test = document.getElementById("testSelect"); var appOption = document.createElement("option"); appOption.setAttribute("value","4"); appOption.appendChild(document.createTextNode("tina shi")); test.appendChild(appOption); } //删除一个选项 function deleteOption() ...{ var test = document.getElementById("testSelect"); test.options[0]=null; test.remove(0); //两种删除选项的方式 } </script> </head> <body onload="deleteOption()"> <textarea rows="10" cols="120" maxlength="50" onkeypress="return TextUtil.isNotMax(this)"> </textarea> <select id="testSelect"> <option value="1">fangzhiyong</option> <option value="2">wanglei</option> <option value="3">kong kai ping</option> </select> </body></html>