Sum values if any as a NULL

[guif]

Hi, I have a table with some values and this part of code do a sum.
Actually I have the problem that if any value in a cell is NULL the result (the sum) i "n/a".

What's need in this code to assign a "0" value if my cell is NULL?

if(this.p.sum){
    r=this.newrow(f);
    for(i;i<t.w;i++){
        var j=r.cells[i];
        if(this.p.sum.exists(i)){
        var s=0, m=t.c[i].format||'';
        for(x=0;x<this.t.l;x++){
            if(t.a[x].s){s+=parseFloat(t.r[x].cells[i].innerHTML.replace(/(\$|\,)/g,''))}
        }
            s=decimals(s,t.c[i].decimals?t.c[i].decimals:2);
                s=isNaN(s)?'n/a':m=='$'?s=s.currency(t.c[i].decimals):s+m;
                   r.cells[i].innerHTML=s
               }else{r.cells[i].innerHTML='&nbsp;'}
        }
}

[Philip M]

var a = null;
if (!a) {a =0}
alert (a);

It was always going to be a game of nutrition. - Commentator Radio Scotland

[guif]

In which part?
My value is the var "s". It's necessary to assign a null value?

[Philip M]

Originally Posted by guif

In which part?
My value is the var "s". It's necessary to assign a null value?

That was just an example. If the value of the variable I named a and you name s is null, change the value to 0.

if (!s) {s=0}