How to find the maximum element in the matrix using function?

 #include<stdio.h>
 int findMax(int **a,int r,int c);
 int main()
 {
  int a[10][10],i,j,max,r,c;
  printf("Enter the number of rows in the matrix\n");
  scanf("%d",&r);
  printf("Enter the number of columns in the matrix\n");
  scanf("%d",&c);
  printf("Enter the elements in the matrix\n");
  for(i=1;i<=r;i++)
  {  for(j=1;j<=c;j++)
     scanf("%d",&[i][j]);
  }
  printf("The matrix is\n");
  for(i=1;i<=r;i++)
  { for(j=1;j<=c;j++)
    scanf("%d",&a[i][j]);
  }printf("\n");}
  max=findMax((int **)a,r,c);
  printf("The maximum elements in the matrix is %d\n",max);
  return 0;
  }
  int findMax(int **a,int r,int c)
  { 
    int t,i,j;
    t=a[1][1];
    for(i=1;i<r;i++)
    { for(j=1;j<c;j++)
    { if(a[i][j]>t)
        t=a[i][j];
    }
    }
   return (t);
  }

Here I attached my coding, I need to find the maximum element present in the matrix using function, I am doing the coding, calling function is not executed, I don't know why, Help me to figure it out.