how to append parameter in URL for default action

hi, i want to add parameters to the url.

normally, it is ok. but if i omit the actionID(using the default actionID index),it always consider the parameter as ActionID and said cannot find the ActionID.

for example,

localhost:8080/index.php?r=user/Follow/userid=1

it always said:The system is unable to find the requested action "userid=1".

but if i changed the url to

localhost:8080/index.php?r=user/Follow/index/userid=1.

it can work properly.

so ,how can i append the parameter while do not need to set the default action in url?

url rules


rules=>array(

  '<module:\w+>/<controller:\w+>/userid=<userid:\d+>'=>'<module>/<controller>/index'

)