<form method="post" action="http://entry.126.com/cgi/login" name="form" onSubmit="return fCheck()">
        <input name="domain" type="hidden" value="126.com" />
        <input name="language" type="hidden" value="0" />
        <input name="bCookie" type="hidden" value="" />
        <div class="ge Ge_h2"></div>
        <p class="MR_pinp"><span>用户名</span>
          <input type="text" name="user" onMouseOver="fEvent('mouseover',this)" onFocus="fEvent('focus',this)" onBlur="fEvent('blur',this)" onMouseOut="fEvent('mouseout',this)" maxlength="30" tabindex="1"/>
          <b class="m126" title="@126.com"></b></p>
        <div class="ge"></div>
        <p class="MR_pinp LH"><span>密 码</span>
          <input onMouseOver="fEvent('mouseover',this)" onFocus="fEvent('focus',this)" onBlur="fEvent('blur',this)" onMouseOut="fEvent('mouseout',this)" name="pass" type="password" size="16" tabindex="2"  maxlength="20"/>
从这段126邮箱的登陆源文件,就可以构造url了,虽然用的是post方式提交信息
但是也可以用get方式提交的,这就是构造url的原理