ELISA experiment - High background (Dec/12/2005 )

Hi everybody these days I'm doing in-house ELISA and I was getting very nice results, and suddenly for the last 2 days I'm getting very high background which means the whole plate is giving the same high yallow color including the control negative and positive,please help me

Hi everybody these days I'm doing in-house ELISA and I was getting very nice results, and suddenly for the last 2 days I'm getting very high background which means the whole plate is giving the same high yallow color including the control negative and positive,please help me