ما سبب مشكلة SyntaxError: expected expression, got '=' ؟

var n;

do
{
    write("Enter number of lines: ");
    n = read();
}
while (n <= 0 || isNaN(n));


if (n %== 0)
{
    n++
}

for (var i = 1; i <= n; i++)
{
    if (i < n / 2)
    {
        for (var k = 1; k = (n / 2) - i + 1; k++)
        {
            write(" ")
        }

        for (var j = 1; j <= (i * 2) - 1; j++)
        {
            write("*")
        }

    }
    else
    {
        for (var k = 1; k < i - (n / 2); k++)
        {
            write(" ")
        }

        for (var j = 1; j = (n * 2) - (i * 2) + 1; j++)
        {
            write("*")
        }
    }

    write("\n")
}

SyntaxError: expected expression, got '='