Register login Client side Error pls help

[Boge]

Hey guys , i was scripting my selfmade script for MTA but when i started the script this error :

attempt to call global 'guiCreateWindow' (a nil value) showed up ! Please help me

Thats the Problem ((i think so )) :

Register.window[1] = guiCreateWindow (84, 214, 650, 270, "Register", false)

  
Register = { 
    button = {}, 
    window = {}, 
    edit = {}, 
    label = {} 
} 
Register.window[1] = guiCreateWindow (84, 214, 650, 270, "Register", false) 
guiWindowSetSizable(Register.window[1], false) 
guiSetAlpha(Register.window[1], 1.00) 
guiSetProperty(Register.window[1], "CaptionColour", "FF48E816") 
  
Register.label[1] = guiCreateLabel(10, 19, 630, 74, "Herzlich wilkommen auf German Nevada Reallife!\n Du bist laut der Datenbank noch nicht registriert ,dies kannst du aber jetzt machen \"{SMILIES_PATH}/icon_smile.gif\" alt=\"\" title=\"Smile\" />\n Bereits registriert ? Wende dich dann bitte an einen Admin!", false, Register.window[1]) 
guiLabelSetColor(Register.label[1], 234, 201, 18) 
Register.label[2] = guiCreateLabel(10, 114, 630, 37, "Username: Der Name", false, Register.window[1]) 
guiSetFont(Register.label[2], "sa-header") 
Register.label[3] = guiCreateLabel(10, 161, 119, 37, "Passwort", false, Register.window[1]) 
guiSetFont(Register.label[3], "sa-header") 
Register.edit[1] = guiCreateEdit(139, 161, 315, 42, "", false, Register.window[1]) 
guiEditSetMasked(Register.edit[1], true) 
Register.button[1] = guiCreateButton(455, 217, 175, 43, "Registrieren", false, Register.window[1]) 
guiSetProperty(Register.button[1], "NormalTextColour", "FFAAAAAA") 
guiSetVisible(Register.window[1],false) 
  
function showRegister ( ) 
    guiSetVisible(Register.window[1],true) 
    showCursor (true) 
end 
addEvent ("showRegister",true) 
addEventHandler ("showRegister",getRootElement(),showRegister) 
  

[Castillo]

You must have put this script as server side, GUI is client side only.