Finding variable names in strings, and replacing with values?

Been working on this one for quite awhile, and it's probably a fairly easy solution, but i can't find it... so thought i would ask. I'm opening a file, and going through it line by line. I need for find places where the line contains %value% and replace it with $value. So if the line says <body bgcolor=%bgcolor% text=%textcolor% link=%linkcolor%>, i need to replace the text where the %% stuff is and set it to $bgcolor,$textcolor,or $linkcolor respectively. - I'm sure this can be done, but i'm just no good w/ the pattern matching stuff... so if anyone has any ideas on this, please let me know!!! Thanks //Nick Richardson //esoteric.web@gte.net //webmaster@moderngarage.com -------------------------------------------------------------- -- We must come to see that the end we seek, is a society -- -- at peace with itself. A society that can live with its -- -- concience. That will be a day not of the white man, not -- -- of the black man... That will be the day of man, as man! -- -- -Dr. Martin Luther King Jr. -- -- -March 25th, 1965 -- --------------------------------------------------------------