People can't go to mi blog

have one error mesage when people go to my blog
Fatal error: Function name must be a string in /membri/pioneertrailespa/blog/wp-content/themes/altervista/header.php(227) : eval()'d code on line 1

cant help me please'

[filsil]

Did you change something in one of the theme files?

Did you change something in one of the theme files?

no... nothing... i can't change files