PHP Text Difference

I am looking for something fast and easy. I basically want to supply two strings (ex: $string1, $string2) I then want a function to show me the differences between the code EXACTLY how it is done here: [login to view URL] Green = replaced text - new text Red = deleted text Please noticed the - and + for where text is deleted and added. The visual presentation of the script must match the wordpress example given. It doesnt matter to me how you do it, for all I care you can rip the source right out of wordpress itself. 24 hour turnaround is a must. So once chosen, please be aware I expect the code in 24 hours.