Format currency amount

HTML

<input type="tSaveext" class="amount" />

JavaScript

function formatAmountNoDecimals( number ) {
    var rgx = /(\d+)(\d{3})/;
    while( rgx.test( number ) ) {
        number = number.replace( rgx, '$1' + ',' + '$3' );
    }
    return number;
}

function formatAmount( number ) {

    // remove all the characters except the numeric values
    number = number.replace( /[^0-9]/g, '' );

    // set the default value
    if( number.length == 0 ) number = "0.00";
    else if( number.length == 1 ) number = "0.0" + number;
    else if( number.length == 2 ) number = "0." + number;
    else number = number.substring( 0, number.length - 2 ) + '.' + number.substring( number.length - 2, number.length );

    // set the precision
    number = new Number( number );
    number = number.toFixed( 2 );    // only works with the "."

    // change the splitter to ","
    number = number.replace( /\./g, ',' );

    // format the amount
    x = number.split( ',' );
    x1 = x[0];
    x2 = x.length > 1 ? ',' + x[1] : '';

    return formatAmountNoDecimals( x1 ) + x2;
}


$(function() {

    $( '.amount' ).keyup( function() {
        $( this ).val( formatAmount( $( this ).val() ) );
    });

});