Why the powershell script is not invoke inside my powershell program - sql-server

Question

Hi i am quite frustrated with powershell. i want to use my powershell script to call another powershell script inside it.
My powershell only do the first part which is download files and does not invoke the following powershell script...
Can not think the reason behind it.. Could anyone help me with that? Thanks!
The Program looks like :
$invocation = (Get-Variable MyInvocation).Value
$directorypath = Split-Path $invocation.MyCommand.Path
Set-Location $directorypath
if ($StepNumber -ne 2) {
$MyName = $MyInvocation.InvocationName
$LogFileName = ".\Logs\" + [System.IO.Path]::GetFileNameWithoutExtension($MyName) + [String]::Format("_{0:yyyy-MM-dd_HH-mm-ss}.Log", (Get-Date))
if (!(Test-Path ".\Logs")) {
$X = New-Item -path . -name Logs -ItemType directory
}
&PowerShell.exe -noProfile -File NSCCMPIDDownload.ps1 2 *>`&1 | Tee $LogFileName
exit
}
## ## ---- STEP2 ------------DownLoad the file from Website
$ErrorActionPreference = "Continue"
Write-Host Running NSCC-MPID-Download at $(Get-Date)
Write-Host ""
## Download the NSCC-MPID-Directory.xls from website
$datestr=$(Get-Date).ToString("yyyy-MM-dd")
$url="http://www.dtcc.com/~/media/Files/Downloads/client-center/NSCC/NSCC-MPID-Directory.xls"
$destination = $directorypath +"/NSCC-MPID-Directory"+"_"+$datestr+".xls"
## if destination does not exsist, creat a new one.
if (!(Test-Path $destination) ) {
New-Item $destination -type file -force
}
$client = new-object System.Net.WebClient
$client.DownloadFile( $url, $destination)
Write-Host Running NSCCMPIDInsertion.ps1
$cmd = "$directorypath\NSCCMPIDInsertion.ps1"
Invoke-Expression "$cmd"
Write-Host Running NSCCMPIDAfterParse.ps1
$cmd = "$directorypath\NSCCMPIDAfterParse.ps1"
Invoke-Expression "$cmd"
Write-Host --------------------------------------------------------------------------
Write-Host Process ended at $(Get-Date)