Mesh Plot Data Dimensions Error

I am trying to generate a 2D meshplot of the data read in from an excel spread sheet. I keep getting an error that says "Data Dimensions must agree." I am trying to plot x on one axis and then function f1,f2,f3 on the other. My code is below. Please help!!!

s=cell(1,4); %%creating cell array

s{1}='x';

s{2}='f1(x)';

s{3}='f2(x)';

s{4}='f3(x)';

col_header= { 'x' 'f1(x)' 'f2(x)' 'f3(x)'}; %%column headers

s{1}=[0; 1; 2; 3; 4; 5; 6; 7];

s{2}=x.^2;

s{3}=sin(x);

s{4}=cos(x);

filename= 'enel519asst1.xlsx'; %%excel filename

xlswrite(filename, col_header ,'A1:D1');

xlswrite(filename, s{1},'A2:D9');

xlswrite(filename, s{2}, 'B2:D9');

xlswrite(filename, s{3}, 'C2:D9');

xlswrite(filename, s{4}, 'D2:D9');

x=xlsread(filename, 'A2:D9' );

f1=xlsread(filename, 'B2:D9');

f2=xlsread(filename, 'C2:D9');

f3=xlsread(filename, 'D2:D9');

mesh( x, f1, f2, f3);