在前台用 JS 清空 服务器控件里面的值 剩余字数验证 邮箱验证 非空验证

functioncountChar(textareaName,counter){

varcou=document.getElementById("mContent").value.length;

document.getElementById(counter).innerHTML=300-cou;

if(cou>299){

document.getElementById("mContent").value=document.getElementById("mContent").value.substring(0,299);

alert("超出长度");

}

}

functionclearControl(){

varInput=prizeshow_div.getElementsByTagName("input");

for(vari=0;i<Input.length;i++){

if(Input[i].type=="text"){

Input[i].value="";

}

}

returnfalse;

}

functionclearControl2(){

vartextarea=prizeshow_div.getElementsByTagName("textarea");

for(vari=0;i<textarea.length;i++){

if(textarea[i].name=="mContent"){

textarea[i].value="";

}

}

returnfalse;

}

<divclass="prizeshow_divc">

<dl>

<dt><span>*</span>企业名：</dt>

<dd>

<asp:TextBoxID="mCompany"class="prizeshow_divinp

rizeshow_wid1"runat="server"></asp:TextBox>

<asp:RequiredFieldValidatorID="valrTel"runat="server"ControlToValidate="mCompany"

Display="Dynamic"ErrorMessage="公司名不能为空！"Font-Size="Small"SetFocusOnError="True"></asp:RequiredFieldValidator>

</dd>

</dl>

<dl>

<dt><span>*</span>姓名：</dt>

<dd>

<asp:TextBoxID="mName"class="prizeshow_divinpprizeshow_wid1"runat="server"></asp:TextBox>

<asp:RequiredFieldValidatorID="RequiredFieldValidator1"runat="server"ControlToValidate="mName"

Display="Dynamic"ErrorMessage="姓名不能为空！"Font-Size="Small"SetFocusOnError="True"></asp:RequiredFieldValidator>

</dd>

</dl>

<dl>

<dt><span>*</span>邮件地址：</dt>

<dd>

<asp:TextBoxID="mMail"class="prizeshow_divinpprizeshow_wid1"runat="server"></asp:TextBox>

<asp:RequiredFieldValidatorID="RequiredFieldValidator2"runat="server"ControlToValidate="mMail"

Display="Dynamic"ErrorMessage="邮件地址不能为空！"Font-Size="Small"SetFocusOnError="True"></asp:RequiredFieldValidator>

<asp:RegularExpressionValidatorID="RegularExpressionValidator1"ControlToValidate="mMail"

EnableClientScript="true"ValidationExpression="^[\w-]+(\.[\w-]+)*@[\w-]+(\.[\w-]+)+$"

runat="server"Display="Dynamic"ErrorMessage="邮件格式不正确！"></asp:RegularExpressionValidator>

</dd>

</dl>

<dd>

<textareaclass="prizeshow_divinpprizeshow_wid2"runat="server"id="mContent"name="msgbox"

onkeydown='countChar("msgbox","counter");'onkeyup='countChar("msgbox","counter");'

rows="5"style="overflow:auto"></textarea>

<br/>

<spanclass="prizeshow_divcspan1">（300字以内，还能输入<spanid="counter"class="prizeshow_divcspan2"><em>300</em></span>字。）</span>

<br/>

<asp:RequiredFieldValidatorID="RequiredFieldValidator4"runat="server"ControlToValidate="mContent"

Display="Dynamic"ErrorMessage="咨询内容不能为空！"Font-Size="Small"SetFocusOnError="True"></asp:RequiredFieldValidator>

</dd>

<inputtype="button"value="取消"onclick="prizeclosediv()"onclick="btnCancel_Click"/>