string replace function

[mshen]

I want to replace part of a long string with another small string.please let me know which functions I can use.

Thanks

[Arc]

I beleive it's
str_replace("StrToReplace","ReplaceWithWhat",$VariableHoldingString)

[mrblom]

If you're familiar with regexp's and find it useful you should look into the preg_replace-function.