Format Exception when trying to parseFloat(String)

Hello, I have a problem with my script. For some reason i get a Format Exception when i try to parseFloat() a String that i get from an InputField.

The Exception:

FormatException: Invalid format. System.Double.Parse (System.String s, NumberStyles style, IFormatProvider provider) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System/Double.cs:209) System.Single.Parse (System.String s) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System/Single.cs:183) UnityScript.Lang.UnityBuiltins.parseFloat (System.String value) ButtonScript.Calc () (at Assets/Scripts/ButtonScript.js:61) UnityEngine.Events.InvokableCall.Invoke (System.Object[] args) (at C:/buildslave/unity/build/Runtime/Export/UnityEvent.cs:144) UnityEngine.Events.InvokableCallList.Invoke (System.Object[] parameters) (at C:/buildslave/unity/build/Runtime/Export/UnityEvent.cs:621) UnityEngine.Events.UnityEventBase.Invoke (System.Object[] parameters) (at C:/buildslave/unity/build/Runtime/Export/UnityEvent.cs:756) UnityEngine.Events.UnityEvent.Invoke () (at C:/buildslave/unity/build/Runtime/Export/UnityEvent_0.cs:53) UnityEngine.UI.Button.Press () (at C:/buildslave/unity/build/Extensions/guisystem/UnityEngine.UI/UI/Core/Button.cs:35) UnityEngine.UI.Button.OnPointerClick (UnityEngine.EventSystems.PointerEventData eventData) (at C:/buildslave/unity/build/Extensions/guisystem/UnityEngine.UI/UI/Core/Button.cs:44) UnityEngine.EventSystems.ExecuteEvents.Execute (IPointerClickHandler handler, UnityEngine.EventSystems.BaseEventData eventData) (at C:/buildslave/unity/build/Extensions/guisystem/UnityEngine.UI/EventSystem/ExecuteEvents.cs:52) UnityEngine.EventSystems.ExecuteEvents.Execute[IPointerClickHandler] (UnityEngine.GameObject target, UnityEngine.EventSystems.BaseEventData eventData, UnityEngine.EventSystems.EventFunction`1 functor) (at C:/buildslave/unity/build/Extensions/guisystem/UnityEngine.UI/EventSystem/ExecuteEvents.cs:269) UnityEngine.EventSystems.EventSystem:Update()

The Code:

"#pragma strict

import UnityEngine.UI;"

 //INPUT STRINGS
 var input1 : String;
 var input2 : String;
 var input3 : String;
 var input4 : String;
 
 //INPUT FIELDS
 var inputF1 : InputField; //input Field 1
 var inputF2 : InputField; //__""__ 2  
 var inputF3 : InputField; //...
 var inputF4 : InputField; //...
 var result : Text;
 
  private final var R : float = 6371000; //Earth's radius in metre
 
 //INPUT VARIABLES
 var d : float; //distance to travel
 var a1 : float; //latitude in dezimals
 var b1 : float; //longitude in dezimals
 var brng : float; //Angle you are going to
 
 function Start () {
 
 }
 
 function Update () {
 
 }
 
 //
 //BUTTON FUNCTIONS
 //
 function ExitButton(){
     Application.Quit();
 }
 
 function InputF1(){
     input1 = inputF1.text;
 }
 
 function InputF2(){
     input2 = inputF2.text;
 }
 
 function InputF3(){
     input3 = inputF3.text;
 }
 
 function InputF4(){
     input4 = inputF4.text;
 }
 
 function Calc(){
     //aFloat = parseFloat(input1);  I TRIED ALL THIS BEVORE WIHT ALL
     //bFloat = parseFloat(input2);    SIMPLE TEST. IT WORKED BACK THEN.
     //flaeche = aFloat * bFloat;
     //result.text = ""+surface;
     d = parseFloat(input3);
     a1 = parseFloat(input1);
     b1 = parseFloat(input2);
     brng = parseFloat(input4);
     var a2 = Mathf.Asin( Mathf.Sin(a1)*Mathf.Cos(d/R) +
                         Mathf.Cos(a1)*Mathf.Sin(d/R)*Mathf.Cos(brng) );
     var b2 = b1 + Mathf.Atan2(Mathf.Sin(brng)*Mathf.Sin(d/R)*Mathf.Cos(a1),
                              Mathf.Cos(d/R)-Mathf.Sin(a1)*Mathf.Sin(a2));
     result.text = a2+"°N "+b2+"°W "; 
 }
 //
 //BUTTON FUNCTIONS END
 //

I have no idea what this Exception is telling me. I am a more or less beginner programmer so please don´t be to harsh on me if the structure of the code is not that good.

The "result" variable is a Text variable which gets displayed in the UI.

Here a picture of the UI. (sry for it beeing German but i think that does not matter that much anyway.)

Thanks in Advance! Lucas