Why does my layout not extend to the bottom of the window when percentages or floats are used?

When I am using width in percentage or float for a Sencha ExtJS panel, then set the left position and width in scientific notation by Sencha ExtJS, the layout stops before the bottom of the window is reached.

See this problem screenshot:

I'm using ExtJS with the VB.NET framework on Chrome v52.

Can you please provide solution for this problem?

I changed the below function in ext-all-debug.js

beforeSetPosition: function (x, y, animate) {
    var pos, x0;

    //change start here
    x = parseInt(x);
    y = parseInt(y);
    //change end here        

    if (!x || Ext.isNumber(x)) {
        pos = { x: x, y : y, anim: animate };
    } else if (Ext.isNumber(x0 = x[0])) { 
        pos = { x : x0, y : x[1], anim: y };
    } else {
        pos = { x: x.x, y: x.y, anim: y }; 
    }

    pos.hasX = Ext.isNumber(pos.x);
    pos.hasY = Ext.isNumber(pos.y);

    
    this.x = pos.x;
    this.y = pos.y;

    return (pos.hasX || pos.hasY) ? pos : null;
},

instead of

beforeSetPosition: function (x, y, animate) {
    var pos, x0;
    
    if (!x || Ext.isNumber(x)) {
        pos = { x: x, y : y, anim: animate };
    } else if (Ext.isNumber(x0 = x[0])) { 
        pos = { x : x0, y : x[1], anim: y };
    } else {
        pos = { x: x.x, y: x.y, anim: y }; 
    }

    pos.hasX = Ext.isNumber(pos.x);
    pos.hasY = Ext.isNumber(pos.y);

    
    this.x = pos.x;
    this.y = pos.y;

    return (pos.hasX || pos.hasY) ? pos : null;
},