singleDigits = new Array();
doubleDigits = new Array();

// Zone 1 postcodes

singleDigits[0]=""
doubleDigits[0]="SG,CB,PE,MK,LU,AL"

// Zone 2 postcodes

singleDigits[1]=""
doubleDigits[1]="NR,IP,CO,CM,SS,EN,IG,WD,HA,RM,UB,TW,KT,DA,BR,CR,SM,ME,LN,DE,NG,LE,CV,NN,OX,HP,SL,RG,GU"

// Zone 3 postcodes

singleDigits[2]="B,S,N,E,W"
doubleDigits[2]="CT,TN,RH,BN,PO,SO,BH,SP,SN,GL,RW,DY,WV,WS,DN,DE,HR,SE,SW,NW,WC,EC,WR,DY,WV,TF,ST,WS"

// Zone 4 postcodes

singleDigits[3]="L,M"
doubleDigits[3]="DT,BA,BS,TA,NP,CF,LD,SA,SY,LL,CH,CW,WA,WN,PR,BL,SK,WF,HD,OL,BB,HX,LS,BD,HG,LA,CA,HU,YO,DL,TS,SR,DH,NE,EX"

function checkPostcode()
{
	zone=-1
	code=document.quoteform.postcode.value.substr(0,2).toUpperCase()
	if(code.substr(1,1)>0){
		for(j=0;j<4;j++){
			singles=singleDigits[j].split(',')
			for(i=0;i<singles.length;i++){
				if(code.substr(0,1)==singles[i])
					zone=j
			}
		}
	}else{
		for(j=0;j<4;j++){
			doubles=doubleDigits[j].split(',')
			for(i=0;i<doubles.length;i++){
				if(code==doubles[i])
					zone=j
			}
		}
	}
	zone++
	return zone
}