Solving Laplace's Equation with Convode and Initial Conditions

[coverband]

Could someone tell me how to enter the following PDE into convode (or some other pde engine - feel free to solve it yourself if you like!).

Its LaPlace's equation

U_xx + U_yy = 0

given U=0 when x=0
U=0 when x=1
U=0 when y=0
U=x when y=1

I've used Convode before but when the initial conditions were U=2 at (x,y)=(2,1) for example...

 

[matematikawan]

I did try using convode some time ago. I think there are examples on that website on how to input the commands. But I'm not sure whether they have example on Laplace equation.

One thing that I don't like about convode is that they give you the feedback in French which I don't understand.