diff --git a/FDTD/engine.h b/FDTD/engine.h
index 5a8da91..a8420e5 100644
--- a/FDTD/engine.h
+++ b/FDTD/engine.h
@@ -5,6 +5,7 @@
 
 class Engine
 {
+	friend class Processing;
 	friend class ProcessVoltage;
 	friend class ProcessCurrent;
 	friend class ProcessFieldsTD;
diff --git a/FDTD/processfields_td.cpp b/FDTD/processfields_td.cpp
index bb6096d..8d1a591 100644
--- a/FDTD/processfields_td.cpp
+++ b/FDTD/processfields_td.cpp
@@ -14,7 +14,7 @@ ProcessFieldsTD::~ProcessFieldsTD()
 
 void ProcessFieldsTD::DumpCellInterpol(ofstream &file)
 {
-		if (DumpType==0)
+	if (DumpType==0)
 	{
 		//create array
 		FDTD_FLOAT**** E_T = Create_N_3DArray(numDLines);
diff --git a/FDTD/processing.cpp b/FDTD/processing.cpp
index 09e89b9..be436c9 100644
--- a/FDTD/processing.cpp
+++ b/FDTD/processing.cpp
@@ -29,6 +29,37 @@ void Processing::DefineStartStopCoord(double* dstart, double* dstop)
 	if (Op->SnapToMesh(dstop,stop)==false) cerr << "Processing::DefineStartStopCoord: Warning: Snapping problem, check stop value!!" << endl;
 }
 
+double Processing::CalcLineIntegral(unsigned int* start, unsigned int* stop, int field)
+{
+	double result=0;
+	FDTD_FLOAT**** array;
+	if (field==0)
+		array=Eng->volt;
+	else if (field==1)
+		array=Eng->curr;
+	else return 0.0;
+
+	unsigned int pos[3]={start[0],start[1],start[2]};
+//	cerr << Eng->volt[1][pos[0]][pos[1]][pos[2]] << endl;
+	for (int n=0;n<3;++n)
+	{
+		if (start[n]<stop[n])
+		{
+			for (;pos[n]<stop[n];++pos[n])
+			{
+				result+=array[n][pos[0]][pos[1]][pos[2]];
+//				cerr << n << " " << pos[0] << " " << pos[1] << " " <<  pos[2] << " " << Eng->volt[n][pos[0]][pos[1]][pos[2]] << endl;
+			}
+		}
+		else
+		{
+			for (;pos[n]>stop[n];--pos[n])
+				result-=array[n][pos[0]][pos[1]][pos[2]];
+		}
+	}
+	return result;
+}
+
 
 void ProcessingArray::AddProcessing(Processing* proc)
 {
diff --git a/FDTD/processing.h b/FDTD/processing.h
index ee67041..0133147 100644
--- a/FDTD/processing.h
+++ b/FDTD/processing.h
@@ -34,6 +34,8 @@ protected:
 
 	unsigned int start[3];
 	unsigned int stop[3];
+
+	double CalcLineIntegral(unsigned int* start, unsigned int* stop, int field);
 };
 
 class ProcessingArray
diff --git a/FDTD/processvoltage.cpp b/FDTD/processvoltage.cpp
index d3683ce..9b0c525 100644
--- a/FDTD/processvoltage.cpp
+++ b/FDTD/processvoltage.cpp
@@ -25,26 +25,7 @@ int ProcessVoltage::Process()
 {
 	if (Enabled==false) return -1;
 	if (CheckTimestep()==false) return GetNextInterval();
-	FDTD_FLOAT voltage=0;
-	unsigned int pos[3]={start[0],start[1],start[2]};
-//	cerr << Eng->volt[1][pos[0]][pos[1]][pos[2]] << endl;
-	for (int n=0;n<3;++n)
-	{
-		if (start[n]<stop[n])
-		{
-			for (;pos[n]<stop[n];++pos[n])
-			{
-				voltage+=Eng->volt[n][pos[0]][pos[1]][pos[2]];
-//				cerr << n << " " << pos[0] << " " << pos[1] << " " <<  pos[2] << " " << Eng->volt[n][pos[0]][pos[1]][pos[2]] << endl;
-			}
-
-		}
-		else
-		{
-			for (;pos[n]>stop[n];--pos[n])
-				voltage-=Eng->volt[n][pos[0]][pos[1]][pos[2]];
-		}
-	}
+	FDTD_FLOAT voltage=CalcLineIntegral(start,stop,0);
 //	cerr << voltage << endl;
 	voltages.push_back(voltage);
 	file << (double)Eng->numTS*Op->GetTimestep() << "\t" << voltage << endl;