Common techniques for developing WAP in PHP

Output in PHP returns the previous level of code:
echo "<a href=". $_server["Http_referer". " > Click here to return </a> ";
The code in WAP is:
<?php
@header ("CONTENT-TYPE:TEXT/VND.WAP.WML");
?>
<?xml version= "1.0" encoding= "Utf-8"?>
<! DOCTYPE WML public "-//wapforum//dtd WML 1.3//en" "HTTP://WWW.WAPFORUM.ORG/DTD/WML13.DTD" >
<wml>
<meta http-equiv= "Expires" content= "0"/>
<card title= "Enter title" >
<do type= "prev" label= "Back Page" >
<prev/>
<!--provide a button can clink to back a step-->
</do><br/>
<!--<anchor>
<prev/> back
</anchor>-->
</card>
</wml>
Code to call in WAP:
<?php
@header ("CONTENT-TYPE:TEXT/VND.WAP.WML");
?>
<?xml version= "1.0" encoding= "Utf-8"?>
<! DOCTYPE WML public "-//wapforum//dtd WML 1.3//en" "HTTP://WWW.WAPFORUM.ORG/DTD/WML13.DTD" >
<wml>
<meta http-equiv= "Expires" content= "0"/>
<card title= "title" >
<p>
<input name= "Phone_no" format= "*m" value= ""/>
<do type= "option" >
<go href= "wtai://wp/mc;$ (phone_no)"/>
</do><br/>
Or
<a href= "wtai://wp/mc;13333333333" > Call </a>
<br/>
</p>
</card>
</wml>

Join WAP Bookmarks <?xml version= "1.0"?> <! DOCTYPE characteristic-list SYSTEM "/dtd/characteristic_list.xml" > <CHARACTERISTIC-LIST> <characteristic type= "Address" > <parm name= "bearer" value= "GPRS"/> <parm name= "PROXY" value= "10.0.0.172"/> <parm name= "PORT" value= "9201"/> <parm name= "Gprs_accesspointname" value= "wap.02826.com"/> <parm name= "Ppp_authtype" value= "PAP"/> </CHARACTERISTIC> <characteristic type= "NAME" > <parm name= "NAME" value= "Wmzsoft GPRS"/> </CHARACTERISTIC> <characteristic type= "The BOOKMARK"/> <parm name= "NAME" value= "02826"/> <parm name= "URL" value= "http://wap.02826.com"/> </CHARACTERISTIC> </CHARACTERISTIC-LIST>