regular xpression

[jansky]

to all guru

sorry my english is not that good .

im a newbie in php and im working on a form.. how can i allow field that has only characters from a -z and numbers plus a space bar and underscore

eregi?

thanks for all help

[laserlight]

You could try something like:

if (preg_match('/^[\da-z_ ]+$/', $str)) {
    echo "valid";
} else {
    echo "invalid";
}