echo<<<EOF
<html>
<body>
<formname="MainForm"method="post"action="http://124.74.239.32/payment/main">
<INPUTtype="text"name="transName"value="{$this->getTranAbbr()}">
<INPUTtype="text"name="Plain"value="{$this->getPlain()}">
<INPUTtype="text"name="Signature"value="{$this->sign($this->getPlain())}">
<INPUTtype="submit"value="submit"/>
</form>
</body>
</html>
EOF;
注意，
1，没有用拼接
2，变量和方法的引用，都用了花括号