on lines 19-21 you have:
$WADbSearch1->addComparisonFromEdit("surname","surname","AND","=",0);
$WADbSearch1->addComparisonFromEdit("forename","forename","AND","=",0);
$WADbSearch1->addComparisonFromEdit("contacts.clientid","clientid","AND","=",0);
you can update it to:
$WADbSearch1->addComparisonFromEdit("surname","surname","AND","Begins With",0);
$WADbSearch1->addComparisonFromEdit("forename","forename","AND","Begins With",0);
$WADbSearch1->addComparisonFromEdit("contacts.clientid","clientid","AND","=",0);