From http://www.w3schools.com (Copyright Refsnes Data)

WML <a> tag

The <a> tag defines an anchor (a link), which allows you to jump from one card/deck to another.

Note: Whenever it is possible, use the <a> tag instead of the <anchor> tag.

Note: It is not allowed to nest anchors.

Syntax

<a href="somefile">
..text..
..image..
</a>

Attributes

Attribute	Value	Description
href	url	REQUIRED. Defines where to go when the user selects the link
title	cdata	Defines a text identifying the link
xml:lang	language_code	Sets the language used in the element
class	cdata	Sets a class name for the element. The class name is case sensitive. An element can be connected to multiple classes. Multiple class names within the class attribute are separated by white space
id	id	Sets a unique name for the element

Examples

<?xml version="1.0"?>
<!DOCTYPE wml PUBLIC "-//WAPFORUM//DTD WML 1.1//EN"
"http://www.wapforum.org/DTD/wml_1.1.xml">

<wml>
<card title="A Tag">
<p>
 <a href="test.wml">Next page</a>
</p>
</card>
</wml>

Complete WML Reference