【html&js】下面的两个代码有什么区别？?报错

两段代码我看了很久一直觉得是一模一样。

// HelloPoint1.js (c) 2012 matsuda
// Vertex shader program
var VSHADER_SOURCE = 
  'void main() {\n' +
  '  gl_Position = vec4(0.0, 0.0, 0.0, 1.0);\n' + // Set the vertex coordinates of the point
  '  gl_PointSize = 10.0;\n' +                    // Set the point size
  '}\n';

// Fragment shader program
var FSHADER_SOURCE =
  'void main() {\n' +
  '  gl_FragColor = vec4(1.0, 0.0, 0.0, 1.0);\n' + // Set the point color
  '}\n';

function main(){
  // Retrieve <canvas> element
  var canvas = document.getElementById('webgl');

  // Get the rendering context for WebGL
  var gl = getWebGLContext(canvas);
  if (!gl) {
    console.log('Failed to get the rendering context for WebGL');
    return;
  }

  // Initialize shaders
  if (!initShaders(gl,VSHADER_SOURCE,FSHADER_SOURCE)) {
    console.log('Failed to intialize shaders.');
    return;
  }

  // Specify the color for clearing <canvas>
  gl.clearColor(0.0, 0.0, 0.0, 1.0);

  // Clear <canvas>
  gl.clear(gl.COLOR_BUFFER_BIT);

  // Draw a point
  gl.drawArrays(gl.POINTS,0,1);
}

//HelloPoint1.js
//顶点着色器程序
var V_SOURCE=
  'void main(){\n'+
  'gl_Position=vec4(0.0,0.0,0.0,1.0);\n'+//设置坐标
  'gl_PointSize=10.0;\n'+//设置尺寸
'}\n';
//片元着色器程序
var F_SOURCE=
  'void main(){\n'+
  'gl_FragColor = vec4(1.0,0.0,0.0,1.0};\n'+//设置颜色
'}\n';

function main(){
	//获取<canvas>元素
	var canvas=document.getElementById('webgl');

	//获取绘图上下文
	var gl=getWebGLContext(canvas);
	if(!gl){
		console.log('Failed to get the rendering context for WEBGL');
		return;
	}
	//初始化着色器程序
	if（!initShaders(gl,V_SOURCE,F_SOURCE)) {
	    console.log('Failed to initialize shaders.');
	    return; 
	}
	//设置<canvas>的背景颜色
	gl.clearColor(0.0,0.0,0.0,1.0);

	//清空<canvas>
	gl.clear(gl.COLOR_BUFFER_BIT);

	//绘制一个顶点
	gl.drawArrays(gl.POINTS,0,1);
}

HTML代码里链接样例页面显示正确，但是链接我的JS文件就报错。不知道哪里有问题。