REFRESH Tag
The <refresh> tag is used to update the current display. 
In other words, whatever card is currently being displayed will be refreshed.
 
The <refresh> tag can only be nested inside an <anchor>, <do>, or <onevent> element. 
This tag can contain one or more <setvar> elements which are used to set new values for named variables. 
 
 SETVAR Tag
The <setvar> tag is used to assign a value to a named variable. 
The assignment is done using a name/value pair where the name is set by the name attribute and the value by the value attribute. 
The name of the variable in the name/value pair must be of correct syntax.
For example, the following code will create a variable named i with a value of 500:
   <setvar name="i" value="500"/>
The <setvar> tag can only be nested in the <go>, <prev>, and <refresh> tags.