function uberprufen() {
	
if(document.daten.first.value == "")
    {
     alert("In order to be considered, the submission must include all required fields marked with a red asterisk ");
     document.daten.first.focus();
     return false;
    }
    
if(document.daten.last.value == "")
    {
     alert("In order to be considered, the submission must include all required fields marked with a red asterisk ");
     document.daten.last.focus();
     return false;
    }
 
if(document.daten.title.value == "")
    {
     alert("In order to be considered, the submission must include all required fields marked with a red asterisk ");
     document.daten.title.focus();
     return false;
    }
    
if(document.daten.co.value == "")
    {
     alert("In order to be considered, the submission must include all required fields marked with a red asterisk ");
     document.daten.co.focus();
     return false;
    }
    
if(document.daten.add1.value == "")
    {
     alert("In order to be considered, the submission must include all required fields marked with a red asterisk ");
     document.daten.add1.focus();
     return false;
    } 
   
if(document.daten.city.value == "")
    {
     alert("In order to be considered, the submission must include all required fields marked with a red asterisk ");
     document.daten.city.focus();
     return false;
    }
 
if(document.daten.st.value == "")
    {
     alert("In order to be considered, the submission must include all required fields marked with a red asterisk ");
     document.daten.st.focus();
     return false;
    }
    
if(document.daten.zip.value == "")
    {
     alert("In order to be considered, the submission must include all required fields marked with a red asterisk ");
     document.daten.zip.focus();
     return false;
    }
    
if(document.daten.country.value == "")
    {
     alert("In order to be considered, the submission must include all required fields marked with a red asterisk ");
     document.daten.country.focus();
     return false;
    }   
    
if(document.daten.phone.value == "")
    {
     alert("In order to be considered, the submission must include all required fields marked with a red asterisk ");
     document.daten.phone.focus();
     return false;
    }
 
if(document.daten.fax.value == "")
    {
     alert("In order to be considered, the submission must include all required fields marked with a red asterisk ");
     document.daten.fax.focus();
     return false;
    }
    
if(document.daten.e_mail.value == "")
    {
     alert("In order to be considered, the submission must include all required fields marked with a red asterisk ");
     document.daten.e_mail.focus();
     return false;
    }
    
if(document.daten.bio.value == "")
    {
     alert("In order to be considered, the submission must include all required fields marked with a red asterisk ");
     document.daten.bio.focus();
     return false;
    }     
   
if(document.daten.Paper.value == "")
    {
     alert("In order to be considered, the submission must include all required fields marked with a red asterisk ");
     document.daten.Paper.focus();
     return false;
    } 
 
 
var counter = 0
if( document.daten.Wireless_Networks.checked == true){counter++;}   
if( document.daten.Mobile_telephony.checked == true){counter++;}    
if( document.daten.Personal_networks.checked == true){counter++;}    
if( document.daten.Industrial_radio_data.checked == true){counter++;}    
if( document.daten.Security.checked == true){counter++;}    
if( document.daten.Embedded_Wireless.checked == true){counter++;}    
if( document.daten.RFID.checked == true){counter++;}    
if( document.daten.Wireless_sensor_networks.checked == true){counter++;}    
if( document.daten.WiMAX.checked == true){counter++;}    
if( document.daten.Wireless_future.checked == true){counter++;}    
if( document.daten.Other.checked == true){counter++;}      


 if(counter > 2){ 
window.document.daten.Wireless_Networks.checked=false;
window.document.daten.Mobile_telephony.checked=false;
window.document.daten.Personal_networks.checked=false;
window.document.daten.Industrial_radio_data.checked=false;
window.document.daten.Security.checked=false;
window.document.daten.Embedded_Wireless.checked=false;
window.document.daten.RFID.checked=false;
window.document.daten.Wireless_sensor_networks.checked=false;
window.document.daten.WiMAX.checked=false;
window.document.daten.Wireless_future.checked=false;
window.document.daten.Other.checked=false;

     alert("You can't check more than 2 Topic areas");
     document.daten.Wireless_Networks.focus();
     return false;
 }

 if(counter == 0){ 
     alert("In order to be considered, the submission must include all required fields marked with a red asterisk ");
     document.daten.Wireless_Networks.focus();
     return false;
 }	
	
	
	
if(document.daten.minute.value == "")
    {
     alert("In order to be considered, the submission must include all required fields marked with a red asterisk ");
     document.daten.minute.focus();
     return false;
    } 		

if(document.daten.Abstract.value == "")
    {
     alert("In order to be considered, the submission must include all required fields marked with a red asterisk ");
     document.daten.Abstract.focus();
     return false;
    } 
    
if(document.daten.Aud.value == "")
    {
     alert("In order to be considered, the submission must include all required fields marked with a red asterisk ");
     document.daten.Aud.focus();
     return false;
    }           
    
if(document.daten.Learn.value == "")
    {
     alert("In order to be considered, the submission must include all required fields marked with a red asterisk ");
     document.daten.Learn.focus();
     return false;
    }    
}