Dur dur buldum :D a++; olan kısmı aşağıya almamız lazım.

function Slayt(){
var a=0;
do{
var sure=2000;
setTimeout('FGalHab2()',sure+0+a*20000);
setTimeout('FGalHab3()',sure+2000+a*20000);
setTimeout('FGalHab4()',sure+4000+a*20000);
setTimeout('FGalHab5()',sure+6000+a*20000);
setTimeout('FGalHab6()',sure+8000+a*20000);
setTimeout('FGalHab7()',sure+10000+a*20000);
setTimeout('FGalHab8()',sure+12000+a*20000);
setTimeout('FGalHab9()',sure+14000+a*20000);
setTimeout('FGalHab10()',sure+16000+a*20000);
setTimeout('FGalHab1()',sure+18000+a*20000);}
a++;
while(a<5)
}