added IsURLValid function

Tools.ps1

@@ -17,7 +17,7 @@ $MSPRoot, $MSPScripts, $MSPTools, $MSPLogs | ForEach-Object {
     }
 }
 
-## Set a datestamp for any log files that might need to be created
+## Set a file prefix for any logs that might need to be created
 $LogFilePrefix = Get-Date -Format "yyyyMMddHHmmss"
 
 ## Function to log activity to the configured log directory
@@ -137,6 +137,11 @@ param(
 )
 $LogName = $MyInvocation.MyCommand
 If ( $Arguments -eq "null" ) { $Arguments = $null }
+If ( $LivePSScript )
+{
+    $URL = "https://dev.emberkom.com/emberkom/${Type}/raw/branch/master/${LivePSScript}.ps1"
+    If ( !(IsURLValid -URL $URL) ) { Log "The specified script does not exist: ${LivePSScript}" -Name $LogName ; Exit }
+}
 If ( $Path ) { If ( !(Test-Path $Path) ) { Log "The specified script does not exist: ${Path}" -Name $LogName ; Exit } }
 If ( ($HaltIfRunning) -and ($ForceClose) -and ( !(IsAdmin) ) ) { Log "Cannot close dependent apps because this task does not have administrative privileges" -Name $LogName ; Exit }
 If ( $HaltIfRunning )
@@ -164,7 +169,6 @@ switch ($PSCmdlet.ParameterSetName)
 {
     'live-ps'
     {
-        $URL = "https://dev.emberkom.com/emberkom/${Type}/raw/branch/master/${LivePSScript}.ps1"
         Log "Retrieving : ${LivePSScript}.ps1" -Name $LogName
         Try { $Script = (New-Object Net.WebClient).DownloadString($URL) }
         Catch { $_.Exception.Message | Log -Name $LogName ; Exit }
@@ -205,6 +209,18 @@ For ($i = 0; $i -le ($Sets - 1); $i++)
 Return [version]$Return.Trim('.')
 }
 
+## Determines whether a URL is valid
+Function IsURLValid
+{
+param([Parameter(Mandatory=$true,ValueFromPipeline=$true)][string]$URL)
+$HTTPRequest = [System.Net.WebRequest]::Create($URL)
+$HTTPResponse = $HTTPRequest.GetResponse()
+$HTTPStatus = [int]$HTTPResponse.StatusCode
+$HTTPResponse.Close()
+If ($HTTPStatus -eq 200) { Return $true }
+Else { Return $false }
+}
+
 ## Function to compare current Windows version with a supplied version
 ## The value supplied must be a string and must include at least 1 decimal
 Function IsWindowsVersion