powershell variable inside quotes

Hi Experts,

I am trying to get the value from a dropdown into the Invoke Command to Start a windows service in a remote system.

When I do write-host $dispname I get the value as "Some Service" but when I try to run the Invoke-Command I get the error below:


function Start-TC{
$dispname = $objAppDropDown.SelectedItem
write-host $dispname
Invoke-Command -Computername $objappsvrname.Text -ScriptBlock { Start-Service -DisplayName "$dispname"  }

}

Error:
With "$dispname" in quotes:

Cannot bind argument to parameter 'DisplayName' because it is an empty string.

Without quotes:
Cannot bind argument to parameter 'DisplayName' because it is null.

Full script attached
scr-1.txt