LENDING MONEY TO A FRIEND

I LENT A (FRIEND) $600 A FEW WEEKS AGO. HE SAID HE NEEDED IT TO PAY HIS RENT AND THAT HE WOULD PAY ME BACK THE FOLLOWING WEEK. I WROTE THE CHECK OUT TO HIS LANDLORD. WELL, ITS BEEN A MONTH AND A HALF AND I CAN'T EVEN GET IN TOUCH WITH HIM.

MY NEXT DOOR NEIGHBOR ALSO RENTS FORM THE SAME LANDLORD AND HAS TOLD ME THAT HE OWES ALOT OF PEOPLE MONEY.

MY QUESTION - CAN I USE THE CASHED CHECK AS PROOF THAT I LENT HIM THE MONEY? I NEVER HAD HIM SIGN ANYTHING (MY MISTAKE). THEIR WOULD BE NO OTHER REASON FOR ME TO GIVE THIS PERSON MONEY (THE LANDLORD). MY NEIGHBOR WILL VOUCH FOR ME THAT MY FRIEND NEEDED THE MONEY AT THAT SPECIFIC TIME TO PAY HIS RENT.

THANKS