Como buscar dados do form e randomizar

Tenho o seguinte formulário:

<input type='checkbox' name='digitos' value='1'>01  <input type='checkbox' name='digitos' value='2'>02  <input type='checkbox' name='digitos' value='3'>03  <input type='checkbox' name='digitos' value='4'>04  <input type='checkbox' name='digitos' value='5'>05  <input type='checkbox' name='digitos' value='6'>06  <input type='checkbox' name='digitos' value='7'>07  <input type='checkbox' name='digitos' value='8'>08  <input type='checkbox' name='digitos' value='9'>09  <input type='checkbox' name='digitos' value='10'>10  <br><input type='checkbox' name='digitos' value='11'>11  <input type='checkbox' name='digitos' value='12'>12  <input type='checkbox' name='digitos' value='13'>13  <input type='checkbox' name='digitos' value='14'>14  <input type='checkbox' name='digitos' value='15'>15  <input type='checkbox' name='digitos' value='16'>16  <input type='checkbox' name='digitos' value='17'>17  <input type='checkbox' name='digitos' value='18'>18  <input type='checkbox' name='digitos' value='19'>19  <input type='checkbox' name='digitos' value='20'>20  <br><input type='checkbox' name='digitos' value='21'>21  <input type='checkbox' name='digitos' value='22'>22  <input type='checkbox' name='digitos' value='23'>23  <input type='checkbox' name='digitos' value='24'>24  <input type='checkbox' name='digitos' value='25'>25  <input type='checkbox' name='digitos' value='26'>26  <input type='checkbox' name='digitos' value='27'>27  <input type='checkbox' name='digitos' value='28'>28  <input type='checkbox' name='digitos' value='29'>29  <input type='checkbox' name='digitos' value='30'>30

Como busco este dados???