I'm trying to replace a string with another but the problem is that the string is matching some other string partially.

For e.g. -

```
Dim x as String = "I am Soham"
x = x.Replace("am","xx")

```

After this replace I would only like the word `am` to replaced with `xx` but because my name also contains `am` its also getting replaced.

The value of x is `I xx Sohxx`. How can I stop this. Please help.