if string conditional

[bekti]

<setvar r>array('text 1', 'text 2', 'text 3')</setvar>
<?=$GLOBALS['tplvars']['r'][array_rand($GLOBALS['tplvars']['r'])?>

don't work

i mean not text 1,2,3..but string like this

<setvar r>array('{string1}', '{string2}', '{string3}')</setvar>
<?=$GLOBALS['tplvars']['r'][array_rand($GLOBALS['tplvars']['r'])?>

i use this one but it doesn't work