ParseException was unhandled

hi developer,
I am using Powershell called through a c# or WPF. Here is ref:
http://blogs.msdn.com/b/kebab/archive/2014/04/28/executing-powershell-scripts-from-c.aspx

I am having a little bit problem with Invoke()

Here is my sample code:
...........................................
string Test = ""Get-Content.............................................................." +
                "ForEach { "+
                "$current = ($_ -split ' ')[-1].Trim() "+
                "If ($current -ne $prev) { $count = 1 } "+
                "................................"+
                "..............................."+
                "............................... "+
                "} | "+
                ".......................................";
PowerShellInstance.AddScript(Test);
PowerShellInstance.Invoke();

...........................................

...........................................

i got error message and it says:

ParseException was unhandled

An unhandled exception of type 'System.Management.Automation.ParseException' occurred in System.Management.Automation.dll

Additional information: Unexpected token 'if' in expression or statement.

Any Idea?

Thanks