replacing text problem

[graziano]

Hello

I have an $output varaiable containing this

<[e-mail]> to: [e-mail] (windows-1250)
<[e-mail]> to: [e-mail] (31 Jan 2007 16:14)
<[e-mail]> to: [e-mail] (31 Jan 2007 0060)
<[e-mail]> to: [e-mail] (31 Jan 2007 16:15:47 -0540)

I am trying to replace all spaces between () with an underscore _
How to do that I am going mad trying and trying.

I am trying to obtain this
echo $output should return this

<[e-mail]> to: [e-mail] (windows-1250)
<[e-mail]> to: [e-mail] (31_Jan 2007_16:14)
<[e-mail]> to: [e-mail] (31_Jan_2007_0060)
<[e-mail]> to: [e-mail] (31_Jan 2007_16:15:47-0540)

Any help ? Thanks

[NogDog]

$output = preg_replace('/\(([^)]+)\)/e', "'('.str_replace(' ', '_', '\\1').')'", $output);

[graziano]

Thank you , it works perfectly !