Login

Today I try to make a login/logout procedure to my account using Application key and certificate generate in previous post.
I'm going to use standard Powershell ISE on Windows 7.
I have upgraded my Powershell to version 4.0 as the standard one was 2.0.
I have to enable script execution by executing:
Set-ExecutionPolicy Unrestricted

Next I'm going to write a bit of code.
First I define global variables, such as URLs, keys,  HTTP headers

1:  #main URLs  
2:  $loginURL="https://identitysso.betfair.com/api/certlogin"  
3:  $logoutURL = "https://identitysso.betfair.com/api/logout"  
4:  #path to cetificate file  
5:  $certFilePath=".\client-2048.crt"  
6:    
7:  #load certificate  
8:  $cert = Get-PfxCertificate $certFilePath  
9:  #get thumbPrint  
10:  $thumbPrint = $cert.Thumbprint  
11:    
12:  #application Key  
13:  $xApplicationKey="my_app_key"  
14:    
15:  #credentials  
16:  $username="username"  
17:  $password="password"  
18:    
19:  #global variables for HTTP requests  
20:  $contentType=“application/x-www-form-urlencoded”  
21:  $header = @{  
22:  "X-Application"=$xApplicationKey  
23:  }  

Second I define a login function:

1:  Function login {  
2:    
3:  #set body  
4:  $body = @{  
5:  "username"=$username  
6:  "password"=$password  
7:  }  
8:    
9:  #call Betfair API NG  
10:  $r=Invoke-RestMethod -uri $loginURL -Body $body -Certificate $cert -CertificateThumbprint $thumbPrint -ContentType $contentType -Header $header -Method "POST" -SessionVariable bsv  
11:    
12:  #chek if login was a success  
13:  if ( $r.loginStatus -ne "SUCCESS" ) {  
14:    Write-Host "ERROR: Loginfailed $($r)"  
15:    exit(1)  
16:  } else {  
17:   Write-Host "Login status: $($r.loginStatus)"  
18:  }  
19:    
20:  #return session token  
21:  return $r.sessionToken  
22:  }  

When I execute this code in Powershell ISE, I got Login status: success on the screen.