<title>无标题页</title> <script type="text/javascript" language="javascript"> function CheckFileType() { var objButton=document.getElementById("Button1");//上传按钮 var objFileUpload=document.getElementById('FileUpload1');//FileUpload var objMSG=document.getElementById('msg');//显示提示信息用的DIV var FileName=new String(objFileUpload.value);//文件名 var extension=new String (FileName.substring(FileName.lastIndexOf(".")+1,FileName.length));//文件扩展名 if(extension=="jpg"||extension=="JPG")//你可以添加扩展名 { objButton.disabled=false;//启用上传按钮 objMSG.innerHTML=""; } else { objButton.disabled=true;//禁用上传按钮 objMSG.innerHTML="请选择正确的文件文件"; } } </script> <form id="form1" runat="server"> <div> <div id="msg"></div> <button id="Button1" runat="server" text="上传" enabled="False"></button> <fileupload id="FileUpload1" runat="server" onchange="javascript:CheckFileType();"></fileupload> </div> </form> [Ctrl+A 全选 注:如需引入外部Js需刷新才能执行]
