proc advance() {
		
	for i=0, totalSections-1 {
		if (secMat.x[i][0] == 1) { IS[ secMat.x[i][1] ].e_extracellular(0:1) = (xtraClamp.i)*xtrares.x[i]:(xtraClamp.i)*xtrares.x[i+1] }
		if (secMat.x[i][0] == 2) { PS[ secMat.x[i][1] ].e_extracellular(0:1) = (xtraClamp.i)*xtrares.x[i]:(xtraClamp.i)*xtrares.x[i+1] }
		if (secMat.x[i][0] == 3) { MAS[ secMat.x[i][1] ].e_extracellular(0:1) = (xtraClamp.i)*xtrares.x[i]:(xtraClamp.i)*xtrares.x[i+1] }
		if (secMat.x[i][0] == 4) { node[ secMat.x[i][1] ].e_extracellular(0:1) = (xtraClamp.i)*xtrares.x[i]:(xtraClamp.i)*xtrares.x[i+1] }

		}

	fadvance()
}