binary trees-finding the maximum and min. value

are the following coding correct for finding the maximum value of a binary tree and to find the minimum value of a bin. tree??????

to find the maximum value:

int Tree::findMax(Node* localroot)

{

int max;

if(localroot!=NULL)

{

findMax(localroot->leftChild);

max=localroot->iData;

findMax(localroot->rightChild);

}

return max;

}//findMax

-----------------------------------------------

to find the minimum value:---

int Tree::findMin(Node* localroot)

{

int arr;

if(localroot!=NULL)

{

findMin(localroot->leftChild);

arr=localroot->iData;

return arr;

}

return -1;

}//findMin