function sprawdz_email(email_address) {
  var email_OK=/^\w([\.-]?\w)*@\w([\.-]?\w)*\.\w{2,4}$/;
  if(email_OK.test(email_address)) {
    return true;
  }
  else {
    return false;
  }
}
function sprawdz_form(nr_form,field_name,field_operation,email_sum) {
  var absence_data=false;
  var field_message=new Array("","");
  var count=new Array(0,0);
  var first_index_focus=new Array(-1,-1);
  var checksum=0;
  switch(nr_form) {
    case 1: var formularz=document.forms.formularz1; break;
    case 2: var formularz=document.forms.formularz2; break;
    case 3: var formularz=document.forms.formularz3; break;
    case 4: var formularz=document.forms.formularz4; break;
    case 5: var formularz=document.forms.formularz5; break;
    case 6: var formularz=document.forms.formularz6; break;
    case 7: var formularz=document.forms.formularz7; break;
    case 8: var formularz=document.forms.formularz8; break;
    case 9: var formularz=document.forms.formularz9; break;
    case 10: var formularz=document.forms.formularz10; break;   
  }
  for(i=0;i<formularz.length;i++) {
    if(field_operation[i]==1 || field_operation[i]==2) {
      if(formularz.elements[i].value=="") {
        if(count[0]>0) {
          field_message[0]+=", ";
        }        
        field_message[0]+=field_name[i];
        absence_data=true;
        if(first_index_focus[0]==-1) {
          first_index_focus[0]=i;
        }          
        count[0]++;
      }
    }
    if(field_operation[i]==2) {    
      if(formularz.elements[i].value!="") {      
        if(!sprawdz_email(formularz.elements[i].value)) {
          if(count[1]>0) {
            field_message[1]+=", ";
          } 
          field_message[1]+=field_name[i];
          absence_data=true;
          if(first_index_focus[1]==-1) {
            first_index_focus[1]=i;
          }          
          count[1]++;                  
        }
      }
    }  
  }
  if(!absence_data) {
    return true;
  }
  else {
    if(field_message[0]!="") {
      if(count[0]==1) {
        alert("Prosimy o wypełnienie następującego pola obowiązkowego: "+field_message[0]+".");
        formularz.elements[first_index_focus[0]].focus();
        return false;      
      }
      else {
        alert("Prosimy o wypełnienie następujących pól obowiązkowych:\n"+field_message[0]+".");
        formularz.elements[first_index_focus[0]].focus();        
        return false;
      }
    }
    else if(field_message[1]!="") {
      if(count[1]==1 && email_sum==1) {
        alert("Podano nieprawidłowy adres email. Prosimy o jego poprawienie.");
        formularz.elements[first_index_focus[1]].focus();        
        return false;
      }
      else if(count[1]==1 && email_sum>1) {
        alert("Podano nieprawidłowy adres email: "+field_message[1]+". Prosimy o jego poprawienie.");
        formularz.elements[first_index_focus[1]].focus();        
        return false;      
      }
      else {
        alert("Podano nieprawidłowe adresy email:\n"+field_message[1]+".\nProsimy o ich poprawienie.");
        formularz.elements[first_index_focus[1]].focus();        
        return false;      
      }
    }
  }    
}
function otworz(strona) {
  switch (strona) {
	case "im1.html": open(strona, "", "height=402, width=520, location=no, menubar=no, scrollbars=no, status=no, toolbar=no, resizable=no"); break;
	case "im2.html": open(strona, "", "height=402, width=520, location=no, menubar=no, scrollbars=no, status=no, toolbar=no, resizable=no"); break;
	case "im3.html": open(strona, "", "height=402, width=520, location=no, menubar=no, scrollbars=no, status=no, toolbar=no, resizable=no"); break;
	case "im4.html": open(strona, "", "height=402, width=520, location=no, menubar=no, scrollbars=no, status=no, toolbar=no, resizable=no"); break; 
	case "im5.html": open(strona, "", "height=402, width=520, location=no, menubar=no, scrollbars=no, status=no, toolbar=no, resizable=no"); break; 
	case "im6.html": open(strona, "", "height=402, width=520, location=no, menubar=no, scrollbars=no, status=no, toolbar=no, resizable=no"); break;
	case "im7.html": open(strona, "", "height=402, width=520, location=no, menubar=no, scrollbars=no, status=no, toolbar=no, resizable=no"); break;
	case "im8.html": open(strona, "", "height=402, width=520, location=no, menubar=no, scrollbars=no, status=no, toolbar=no, resizable=no"); break;
	case "im9.html": open(strona, "", "height=402, width=520, location=no, menubar=no, scrollbars=no, status=no, toolbar=no, resizable=no"); break;
	case "im_test.html": open(strona, "", "height=435, width=500, location=no, menubar=no, scrollbars=no, status=no, toolbar=no, resizable=no, top=0, left=0"); break;
  }
}