var numArr = new Array("0","1","2","3","4","5","6","7","8","9"); // Add elements here

totalNumbers=6 // how many 
numbersRange=numArr.length //range 

function generate(){ 

if(totalNumbers>numbersRange){ 
totalNumbers=numbersRange 
} 

firstRun=true 
selectedNums=new Array() 

for(var i=0;i<totalNumbers;i++){ 
chosen=false 
rndnum=Math.floor(Math.random()*numbersRange) 

if(!firstRun){ 

for(var j=0;j<selectedNums.length;j++){ 
if(rndnum==selectedNums[j]){ 
chosen=true 
i-- 
} 
} 

} 

if(!chosen){ 
selectedNums[i]=rndnum 
firstRun=false 
} 

} 

document.getElementById("reference").value="" // 

for(var k=0;k<selectedNums.length;k++){

document.getElementById("reference").value+=selectedNums[k] // 

}

} 

onload=generate