My simple cheat my homework prog. :) but it dont work.

[factor777]

OK today i desided no more hard math work and i made a program to increase my efficiancy.
calling a function that does stuff aint that easy like vb. please tell me what im forgetting.

#include <stdio.h>
#include <iostream.h>

const double Pi = 3.141592654;
char choice;

int main()
{
	printf("a.	Cylinder\n");
	printf("b.	Cone\n");
	printf("c.	Prism\n");
	printf("d.	Pyramid\n");
	printf("--------------\n");
	printf("x.	Exit\n");

	cin>>choice;

	switch ( choice ){
	case 'a':
		  LaSaCylinder();
		  break;
	case 'x':
		return 0;
	};

};
//////////////////////////
//Cylinder Calculation ///
//////////////////////////
//LA = Lateral Area    ///
//////////////////////////
//SA = Surface Area    ///
//////////////////////////
void LaSaCylinder(int radius, int hieght, double LA, double SA);
{ 
	cout << "What is the radius of the base?\n";
	cin >> radius;
	cout << "What is the height of the Cylinder?\n";
	cin >> height;

	LA = (2 * Pi * radius) * height;
	SA = LA + (2 * (Pi * (radius^2)));

	cout << LA << " is the Lateral area.\n";
	cout << SA << " is the Surface area.\n";
};

this has been more work than i thought! m8's! Heres my craptacular error!
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--------------------Configuration: Math - Win32 Debug--------------------
Compiling...
Math.cpp
D:\Ftp\BIN\Math\Math.cpp(21) : error C2065: 'LaSaCylinder' : undeclared identifier
D:\Ftp\BIN\Math\Math.cpp(35) : error C2373: 'LaSaCylinder' : redefinition; different type modifiers
D:\Ftp\BIN\Math\Math.cpp(36) : error C2447: missing function header (old-style formal list?)
Error executing cl.exe.

Math.exe - 3 error(s), 0 warning(s)
---------------------------------------------------------------------------------------

it just Got worse!