Help with printing a string

I have a theoretical plot for the fresnel diffration pattern, however i want maple to show the values plotted on the x and y cordinates. How do i do this. Please explain in simple terms

heres my code

> fresdi:= proc(a,b) (FresnelC(a) - FresnelC(b))^2 + (FresnelS(a) - FresnelS(b))^2 end;

fresdi := proc(a, b)

(FresnelC(a) - FresnelC(b))^2 + (FresnelS(a) - FresnelS(b))^2

end proc;

> v:=1.48;

v := 1.48

> umin:=-6; umax:=6;

umin := -6

umax := 6

> plot( fresdi(u-(v/2),u+(v/2)), u=umin..umax,title=cat(`Fresnel diffraction from slits of width v=`,

> convert(v,string)), axes=boxed, labels=[`Distance across diffraction plane, u`,`I(u)`]);

Cheers