Search SQL Server Error Logs

<#
    .SYNOPSIS
        Get-ISqlFilteredErrorLog
    .DESCRIPTION
        Locate keywords in error log
    .PARAMETER serverInstance
        SQL Server instance
    .PARAMETER filter
        Keyword to use for filtering the search
    .PARAMETER errorLog
        Number of error log to search. Leave blank to search current
    .EXAMPLE
        .\Get-ISqlFilteredErrorLog -serverInstance MyServer\SQL2012 -filter Error
    .INPUTS
    .OUTPUTS
    .NOTES
    .LINK
#>

param (
    [string]$serverInstance = "$(Read-Host 'Server Instance' [e.g. Server01\SQL2012])",
    [string]$filter = "$(Read-Host 'Keyword Filter' [e.g. Error])",
    [int]$logNumber = "$(Read-Host 'Log Number 0=Current' [e.g. 1])"
)

begin {
    [void][System.Reflection.Assembly]::LoadWithPartialName('Microsoft.SqlServer.SMO')
}
process {
    try {
        $srv = New-Object "Microsoft.SqlServer.Management.Smo.Server" $serverInstance

        If ($logNumber -eq 0) {
            If ($filter -eq "") {
                $output = $srv.ReadErrorLog()
            } else {
                $output = $srv.ReadErrorLog() | where {$_.Text -like "$filter*"}
            }
        } else {
            If ($filter -eq "") {
                $output = $srv.ReadErrorLog()
            } else {
                $output = $srv.ReadErrorLog($logNumber) | where {$_.Text -like "$filter*"}
            }
        }

        Write-Output $output
    }
    catch [Exception] {
        Write-Error $Error[0]
        $err = $_.Exception
        while ( $err.InnerException ) {
            $err = $err.InnerException
            Write-Output $err.Message
        }
    }
}