var x=new Array(); var y=new Array(); var number; function sample(){ x[1]=250; y[1]=50; x[2]=150; y[2]=150; x[3]=260; y[3]=250; x[4]=360; y[4]=150; number=4; miny=6000; s1=0; for(s=1;s<number+1;s++){ if(y[s]<miny)s1=s; if(y[s]<miny)miny=y[s]; } maxy=0; s2=0; for(s=1;s<number+1;s++){ if(y[s]>maxy)s2=s; if(y[s]>maxy)maxy=y[s]; } alert(s1+","+s2); }