I am interested in purchasing this hat, and as a tennis player who sweats profusely, i need to make sure i will not be wasting my money on this product (sweat marks). Could someone tell me if this product can be machine or hand washed... and could you give me more details into what can be done with it.. Thank you in advance 
http://www.prodirecttennis.com/prodinfo.asp?PID=PDT-302-009-483&DEPT=302&BRAND=009&SS=1&AFFID=79
http://www.tennis-warehouse.com/Nike_Roger_Federer_RF_Hybrid_Hat_Bluegrass/descpageMANIKE-NRFHBWBG.html
http://www.prodirecttennis.com/prodinfo.asp?PID=PDT-302-009-483&DEPT=302&BRAND=009&SS=1&AFFID=79
http://www.tennis-warehouse.com/Nike_Roger_Federer_RF_Hybrid_Hat_Bluegrass/descpageMANIKE-NRFHBWBG.html