Write a PHP function to perform salting and hashing. The function should accept one string parameter and return another string variable after both salting and hashing are performed. Salting should be done at the beginning and at the end of the string parameter. A basic code is provided below (values of the two salting variables are also provided):

function processSaltingAndHashing($string){

$salt1 = 'er$56Y';

$salt2 = 'ut9*&T';

}