function [indexInY] = indexXinY(X,Y)

lenX = length(X);
lenY = length(Y);
[Xs, IX] = sort(X);
[Ys, IY] = sort(Y);

indY = 1;
indexXSinYS = zeros(1,lenX); %indexXSinYS(i) holds the index of Xs in the Y 

for indX = 1:lenX

    while (indY<=lenY && mystrcmpi(Xs{indX}, Ys{indY})>0)
        indY = indY+1;
    end
    if indY>lenY
        for i=indX:lenX
            indexXSinYS(i) = 0;
        end
        break;
    end
    if mystrcmpi(Xs{indX}, Ys{indY})== 0
        indexXSinYS(indX) = indY;
    else
        indexXSinYS(indX) = 0;
    end
end

indexInY = zeros(1, lenX);
for i=1:lenX
    if indexXSinYS(i) == 0
        indexInY(IX(i)) = 0;
    else
        indexInY(IX(i)) = IY(indexXSinYS(i));
    end
end