Transpose Matrix array manipulation

Hi guys I am working on this program
Array Manipulation - Transpose of a Square Matrix: This program reads a matrix (two dimensional array), displays its contents, transposes it and then displays the transposed matrix.
and here's the code
Code:
```#include <iostream.h>

const int arraySize = 3;

void displayMatrix(int a[][arraySize]);
void transposeMatrix(int a[][arraySize]);

void main(void)
{

int a[arraySize][arraySize];

cout<<"\n\n"<<"The original matrix is:"<<'\n'; //Display the matrix

displayMatrix(a);

transposeMatrix(a); //transpose the matrix

cout<<"\n\n"<<"The transposed matrix is:" << '\n'; //Display the transposed matrix
displayMatrix(a);
}

{
int row, col;

for(row = 0; row<arraySize;row++)
{
for(col=0; col<arraySize; col++)
{
cout<<"\n"<<"Enter"<<row<<","<<col<<"element";
cin>>arr[row][col];
}
cout<<'\n';
}
}
void displayMatrix(int a[][arraySize])
{
int row,col;
for (row=0; row<arraySize;row++)
{
for(col=0; col<arraySize; col++)
{
cout<<a[row][col]<<'\t';
}
cout<<'\n';
}
}
void trnasposeMatrix(int a[][arraySize])
{
int row,col;
int temp;
for(row=0; row < arraySize; row++)
{
for(col=row; col<arraySize;col++)
{
temp=a[row][col]; //save the original value in the temp variable
a[row][col]=a[col][row];
a[col][row]=temp; //take out the original value
}
}
}```
When I compile the program it says 'mail' must return 'int' I think everything is right please help me on this....