Thread: Help with validation rule

Hi I am writing some code but need a validation in one part

Code:

for(int i=0; i < size; i++)
  {
  system("cls");
cout <<"\nPlease enter the Cars registration: " << (i+1) << ": ";
cin >> autos[i].carreg;
cout <<"\nPlease enter the make of Car: ";
cin >> autos[i].carmake;
 cout <<"\nPlease enter the Model of Car: ";
cin >> autos[i].carmodel;
 cout <<"\nPlease enter the Cars milage: ";
cin >> autos[i].carmile;
cout <<"\nPlease enter the Cars age: ";
cin >> autos[i].carage;
cout<<"\n";
  }

I need it so that you cannot enter a minus value for car age or milage, im sure i know this but my mind has gone totally blank.
Thanks in advance for any help.
snooki