[ironskillz1]

Updated! 2.0

/* Plugin generated by AMXX-Studio */
#include <amxmodx>
#include <amxmisc>
#include <dhudmessage>
#define PLUGIN "HarlemShake"
#define VERSION "2.0"
#define AUTHOR "ironskillz1"

public plugin_init() {
 register_plugin(PLUGIN, VERSION, AUTHOR)
 
 register_clcmd( "say /shake", "Shake" ) // Command!
 register_clcmd( "say /harlemshake", "Shake" ) // Command!
} 
public plugin_precache()
{
 precache_generic("sound/harlemshake.mp3") // sound
}
public Shake(id) 
{
 if(!(get_user_flags(id) & ADMIN_CFG)) // is user admin?
 {
  client_print(id, print_chat, "Only ADMINS can use this command!") // if not print this 
 }
 set_task(0.1,"Music"); // start music
 set_task(0.1,"Dhud"); // Dhud message
 set_task(17.0,"Slap"); // start slaping 
 set_task(30.0,"Remove"); // remove slaping
}
public Music() 
{
 client_cmd(0, "mp3 play ^"sound/harlemshake.mp3^"") // play music
}
public Dhud() 
{
 set_dhudmessage(0, 30, 50, 0.01, 0.15, 0, 1.0, 1.0, 0.1, 0.2)
 show_dhudmessage ( 0, ".:: Harlem Shake Event ::.") // print permanent dhud message in left top corner
 set_task(0.1,"Dhud");
}
public Slap() // SLAP !!
{
 new iTotal, all[32]
 get_players( all, iTotal, "a")
 
 for ( new i = 0; i < iTotal; i++ ) 
 {  
         new id = all[i]
         user_slap( id, 0 )
 }
 
 set_task(0.5,"Slap"); // SLAP TIME
}
public Remove() // remove slap!
{
 remove_task();
}

Here is the song
put it in cstrike/sound/harlemshake.mp3