Trimming Words

I have a database field that is a memo type. I would like to be able to only display the first 50 words from the database. I would like for it to show ..... after about 50 words.

I am using <%=Content %>. How do I trim this field to show only 50 words and then ....?

I tried the following code:
Function LengthTrim(input, length)
If Len(input) > length Then
Return Left(input, length) + "..."
Else
Return input
End If
End Function

then <%= LengthTrim(Content, 50) %>

But it would not work. I got the following error message:

Microsoft VBScript runtime error '800a01f4'Variable is undefined: 'Return' .