YAP,When ya load up the game, relationships will be all reset and turrets will attack ya.

Create new cfg file using notepad in folder :/your hl2 dir/hl2/cfg/.name it turret. now open the valve.rc with notepad and you'll see something loke this

// load the base configuration
//exec default.cfg

// Setup custom controller
exec joystick.cfg

// run a user script file if present
exec autoexec.cfg
//
// stuff command line statements
//
stuffcmds

// display the startup level
startupmenu

Now replace this

// run a user script file if present
exec autoexec.cfg
exec turret.cfg

You have to put your setrelationship command in turret.cfg like mine.

ent_fire gun1 setrelationship "player D_LI 99

ent_fire gun1 setrelationship "npc_combine_s D_HT 99"

ent_fire gun1 setrelationship "npc_metropolice D_HT 99

bind 7 "npc_create npc_turret_floor"

bind 8 "ent_setname gun1"

bind 9 "exec turret"

bind 0 "ent_fire gun1 enable"

So now you can spawn turret with 7 and setname with 8, 9 make it like you and hate the combines and 0 to enable it.