$ErrorActionPreference = 'Stop'
$root = Split-Path -Parent $PSScriptRoot
$hta = Get-Content -LiteralPath (Join-Path $root 'MassMailer.hta') -Raw
$match = [regex]::Match($hta, '(?s)<script language="JScript" type="text/javascript">(.*?)</script>')
if (-not $match.Success) { throw 'HTA JScript block not found' }
$check = Join-Path $root ('temp\hta-syntax-' + [guid]::NewGuid().ToString('N') + '.js')
try {
    [System.IO.File]::WriteAllText($check, $match.Groups[1].Value)
    $scriptHost = Join-Path $env:SystemRoot 'SysWOW64\cscript.exe'
    & $scriptHost //nologo //E:JScript $check
    if ($LASTEXITCODE -ne 0) { throw 'HTA JScript syntax failed' }
    Write-Output 'HTA JScript syntax passed'
}
finally { if (Test-Path -LiteralPath $check) { Remove-Item -LiteralPath $check -Force } }