NAME - Required.
This is a parameter name,
whose value will determine if the conditional passed or fails.
If NAME is not specified,
the conditional will consider to always fail.
OP - defaults to == (numeric equality).
If VALUE is specified,
this will be how NAME and VALUE are compared.
OP can be any of the 6 numeric comparision operators or the 6 string comparision operators.
VALUE - if this is specified,
OP will be checked.
This is a standard attribute,
so if you want a parameter,
prepend it with '$'.
IS - If there is no VALUE attribute,
this will be checked.
IS can be either 'FALSE' or 'TRUE'.
The boolean of NAME will be compared and the conditional will branch appropriately.
If NAME has no value,
this will fail.
NONE - If there is no IS and no VALUE,
then an attempt will be made to find the variable defined by NAME.
If it exists and is true,
the condition will succeed.
it will fail.
<if name="__PAGE__" OP="!=" VALUE="__LAST_PAGE__">
... Children execute if the current page is not the last page ...
<if name="Param1" OP="eq" VALUE="$Param2">
... Children execute if Param1 is string-wise equals to Param2 ...