I need for a user to be able to resize a panel using at least one corner at runtime. I did this by making a panel and placing a small picturebox in the bottom left corner. I'm only testing it, so I just gave both the picturebox and panel black borders so I could test my code. Here's what I came up with:

Code:
Public Class Form1
    Dim isresize As Boolean = False
    Dim currentx As Integer
    Dim currenty As Integer
    Private Sub PictureBox1_MouseDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseDown
        isresize = True
        currentx = e.X
        currenty = e.Y
    End Sub

    Private Sub PictureBox1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseMove
        If isresize = True Then
            If e.X < currentx Then
                Panel1.Width = Panel1.Width - (currentx - e.X)
                currentx = e.X
            End If

            If e.X > currentx Then
                Panel1.Width = Panel1.Width + (e.X - currentx)
                currentx = e.X
            End If

            If e.Y < currenty Then
                Panel1.Height = Panel1.Height - (currenty - e.Y)
                currenty = e.Y

            End If

            If e.Y > currenty Then
                Panel1.Height = Panel1.Height + (e.Y - currenty)
                currenty = e.Y
            End If
        End If
    End Sub

    Private Sub PictureBox1_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseUp
        isresize = False
    End Sub
End Class
Yet when I try it, my panel flickers and the picturebox doesn't keep up with my cursor. Is there any easy way to revise my code? Thanks.