function levenshteinDistance(s,t){
    if(s.length>t.length){
        var temp=s;
        s=t;
        t=temp;
        delete temp;
    }
    var n=s.length;
    var m=t.length;
    if(m==0){
        return n;
    }
    else if(n==0){
        return m;
    }
    var v0=[];
    for(var i=0;i<=m;i++){
        v0[i]=i;
    }
    var v1=new Array(n+1);
    var cost=0;
    for(var i=1;i<=n;i++){
        if(i>1){
            v0=v1.slice(0);
        }
        v1[0]=i;
        for(var j=1;j<=m;j++){
            if(s[i-1].toLowerCase()==t[j-1].toLowerCase()){
                cost=0;
            }
            else{
                cost=1;
            }
            v1[j]=Math.min.call(null,v1[j-1]+1,v0[j]+1,v0[j-1]+cost);
        }
    }
    return v1.pop();
}

//Test
levenshteinDistance("gUMBO","GAMBOL");//output 2