need help - Move or merge two windows into one gui

hello guys, below i have a little powershell chat script. after starting the script it opens two seperate windows for writing the message and receving it from the other chat partner. is it possible to put these two windows into one simple gui like every window over each other and adjust the size? thanks for your help.

$ServerShare = "\\nas1\chat"

function Enter-Chat 
{
  param
  (
    [Parameter(Mandatory)]
    [string]
    $ChatChannelName,
    
    [string]
    $Name = $env:USERNAME,
    
    [Switch]
    $ShowOldPosts,
    
    $HomeShare = $ServerShare
    
  )
  
  if ($ShowOldPosts)
  {
    $Option = ''
  }
  else
  {
    $Option = '-Tail 0'
  }

  $Path = Join-Path -Path $HomeShare -ChildPath "$ChatChannelName.txt"
  $exists = Test-Path -Path $Path
  if ($exists -eq $false)
  {
    $null = New-Item -Path $Path -Force -ItemType File
  }

  $process = Start-Process -FilePath powershell -ArgumentList "-noprofile -windowstyle hidden -command Get-COntent -Path '$Path' $Option -Wait | Out-GridView -Title 'Chat: [$ChatChannelName]'" -PassThru

  Write-Host "To exit, enter: quit""[$Name entered the chat]" | Add-Content -Path $Path
  do
  {
    Write-Host "[$ChatChannelName]: " -ForegroundColor Green -NoNewline
    $inputText = Read-Host 
    $isStopCommand = 'quit','exit','stop','leave' -contains $inputText
    if ($isStopCommand -eq $false)
    {"[$Name] $inputText" | Add-Content -Path $Path
    }
  } until ($isStopCommand -eq $true)"[$Name left the chat]" | Add-Content -Path $Path
  $process | Stop-Process
}
function Get-ChatChannel
{
  param
  (
    $HomeShare = $ServerShare
  )

  Get-ChildItem -Path $HomeShare -Filter *.txt -File |
    ForEach-Object {
      [PSCustomObject]@{
        ChannelName = [System.IO.Path]::GetFileNameWithoutExtension($_.Name)
        LastActive = $_.LastWriteTime
        Started = $_.CreationTime
      }
    }
}    

$Username = read-host "Username"
Enter-Chat -ChatChannelName Chat -Name $username -ShowOldPosts