Richtextbox not finding all words

Hi all, I have a vb.net program that I want to search a webpage that has Hyperlinks and if the Hyperlink contains a certain word, it will show a message.

Here is my code :

Dim all As HtmlElementCollection = WebBrowser1.document.All

For Each wpelement As HtmlElement In all

If wpelement.GetAttribute("value") = (richtextbox1.text) Then

messagebox.show( "Yes")
End If
Next

when I input the word into the richtextbox1.text for insistence " Welcome To My House"), the messagebox wont appear, if I only input Welcome or House, just one word, the messagebox will appear. I need help it seems like the richtextbox only finds some of the words and only 1 word, I need to be able to find exact word or if any matching words.

Thanks