NOW I USED THIS CODE AND IT WORKS
Dim PNO1 As String = "11022"
PNO1 = " + inputtxt.Text + "
Image1.ImageUrl = "~/Photos/" + PNO + ".jpg"
'Image1.ImageUrl = "C:/Awing/Photos/" + PNO + ".jpg"
BUT WHEN I CHANGE THE LOCATION TO c:\AWING\PHOTOS FOLDER IT IS NOT WORKING. EXACTLY MY PHOTOS+DATABASE IS LOCATED IN C:AWING FOLDER