function berechne()
									{
									 a = parseInt(document.signup.SAA.value);
									 b = parseInt((document.signup.SMM.value)-1);
									 c = parseInt(document.signup.SGG.value);
									 f = new Date(a,b,c);
									 g = new Date();
									
									 minuten = g.getMinutes()-f.getMinutes();
									 stunden = g.getHours()-f.getHours();
									 birth_de = g.getDate()-f.getDate();
									 birth_me = g.getMonth()-f.getMonth();
									 birth_ye = g.getYear()-f.getYear();
									 if(birth_de<0){birth_de = 30+birth_de; birth_me--;}
									 if(birth_me<0){birth_me = 12+birth_me; birth_ye--;}
									 if(birth_ye > 2000){birth_ye = birth_ye-2000}
									 if(birth_ye > 1900){birth_ye = birth_ye-1900}
									
									 if (signup.SAA.value==0) {  signup.my_age.value =''; }
									 else if (birth_ye > 1 ) {  signup.my_age.value = birth_ye }
									 else {  signup.my_age.value = 0 }
									 }