Why i get an error on objShell - VBS HTML

I don't know why i get an error on the "Set objShell =" string of this VBS code (it's into an html). I'm working on a .HTA launcher for a game named Doom and this vbs script serves to select the game and launch it with some parameters (sorry for bad english)

Dim pwad, warp, skill, execDoom, execPwad, execWarp, execSkill, rep, fso, file, OpFScript, WScript, objShell
Set objShell = WScript.CreateObject("WScript.Shell")
Set pwad = document.GetElementById("inpFILE")
Set warp = document.GetElementById("inpMAP")
Set skill = document.GetElementById("inpSKILL")

Set fso = CreateObject("Scripting.FileSystemObject")
Set file = fso.OpenTextFile("C:\ZDLRemastered\launcher\ScriptOpFile.txt", 1)
OpFScript = file.ReadAll
Function GetFileDlgEx(sIniDir,sFilter,sTitle) 
Set oDlg = CreateObject("WScript.Shell").Exec("mshta.exe & OpFScript")
oDlg.StdIn.Write "var iniDir='" & sIniDir & "';var filter='" & sFilter & "';var title='" & sTitle & "';" 
GetFileDlgEx = oDlg.StdOut.ReadAll 
End Function
sFilter = "Doom Archive (*.wad)|*.wad|"  
sTitle = "Select a Doom IWAD"
rep = GetFileDlgEx(Replace(sIniDir,"\","\\"),sFilter,sTitle)

execDoom = "C:\ZDLRemastered\gzdoom\gzdoom.exe -config C:\ZDLRemastered\gzdoom\gzconfig.ini -iwad "
execPwad = " -file "
execWarp = " -warp "
execSkill = " -skill "
objShell.Run execDoom & chr(34) & rep & chr(34) & execPwad & chr(34) & pwad & chr(34) & execWarp & chr(34) & warp & chr(34) & execSkill & chr(34) & skill & chr(34)

This is the error: -necessary object: " -