function empty_check(field){
  switch(field.name){
    case "firstName":
      if(field.value == ""){
        field.style.backgroundColor='red';
      }else{
        field.style.backgroundColor='white';
      }
    break;
    case "lastName":
      if(field.value == ""){
        field.style.backgroundColor='red';
      }else{
        field.style.backgroundColor='white';
      }
    break;
    case "business":
      if(field.value == ""){
        field.style.backgroundColor='red';
      }else{
        field.style.backgroundColor='white';
      }
    break;
    case "businessAddress1":
      if(field.value == ""){
        field.style.backgroundColor='red';
      }else{
        field.style.backgroundColor='white';
      }
    break;
    case "businessCity":
      if(field.value == ""){
        field.style.backgroundColor='red';
      }else{
        field.style.backgroundColor='white';
      }
    break;
    case "businessState":
      if(field.value == ""){
        field.style.backgroundColor='red';
      }else{
        field.style.backgroundColor='white';
      }
    break;
    case "businessZip":
      if(field.value == ""){
        field.style.backgroundColor='red';
      }else{
        field.style.backgroundColor='white';
      }
    break;
    case "phone":
      if(field.value == ""){
        field.style.backgroundColor='red';
      }else{
        field.style.backgroundColor='white';
      }
    break;
    case "email":
      if(field.value == ""){
        field.style.backgroundColor='red';
      }else{
        field.style.backgroundColor='white';
      }
    break;
    case "username":
      if(field.value == ""){
        field.style.backgroundColor='red';
      }else{
        field.style.backgroundColor='white';
      }
    break;
    case "password":
      if(field.value == ""){
        field.style.backgroundColor='red';
      }else{
        field.style.backgroundColor='white';
      }
    break;
    case "passwordAgain":
      if(field.value == ""){
        field.style.backgroundColor='red';
      }else{
        field.style.backgroundColor='white';
      }
    break;
    case "trainingCode":
      if(field.value == ""){
        field.style.backgroundColor='red';
      }else{
        field.style.backgroundColor='white';
      }
    break;
    case "securityCode":
      if(field.value == ""){
        field.style.backgroundColor='red';
      }else{
        field.style.backgroundColor='white';
      }
    break;
  }
}