Count biggest Pallandrome in string

function checkPallandrome(s){
var count = 0;
var biggestCount = 0;

if(s.length == 0){console.log(0); return;}
if(s.length == 1){console.log(1); return;}
for(let i =1;i<s.length;i++){
if(s[i] == s[i-1]){
for(let j = i-1;j>=0;j--){
if(i+(i-j) <= s.length){
if(s[j]==s[i+(i-j-1)])
{
count+=2;
}else{
biggestCount = biggestCount>count? biggestCount: count;
break;
}
}
}
}
else if(s[i] == s[i-2]){
count =1;
for(let j = i-2;j>=0;j--){
if(i+(i-j-1) <= s.length){
if(s[j]==s[i+(i-j-2)])
{
count+=2;
}else{
biggestCount = biggestCount>count? biggestCount: count;
break;
}
}
}
}
biggestCount = biggestCount>count? biggestCount: count;
count = 0;

}

console.log(biggestCount);

}