Itunes is detecting my iphone in recovery mode whereas my phone is plugged in with normal mode

I tried to sync my iphone today but the itunes says it can nt read the cntents of my iphone so i have to restore it. It says it will erase all my data n will restore it from d recent backup but the problem is i dont hav any backup of my iphone. So will it perform a backup during d restoring process or i hav to arrange a backup before restoring? N if backup is required how can i do so coz itunes cud nt back up my iphone?