java script - how to send parameters from Form of HTML to java script

there are two ways that you can send parameters from for of HTML to java script
1.
java script
function count(form)
{
var a=eval(form.number1.value);
var b=eval(form.number2.value);
//get parameters from form
}
-HTML part
<input type=text name=number1>
<input type=text name=number2>
<input type=Button name=submit onClick=count(this.form)//you send the even on click to the function count at java script

2.
Java script
function count(number1,number2)// you get two parameters number1 and number2 directly from form
{
 var c;
c=a*b;
}
-HTML part
<input type=text name=number1>
<input type=text name=number2>
<input type=Button name=submit onClick=count(number1.value , number2.value)//you send two paremeters to the function count