js 自定义提示框 适配火狐，谷歌，IE

 function PromptBox(id) {
     this.value="";
     this.shadowId=id;
     this.divId=id+1;
    this.div1Id=id+2;

};


PromptBox.prototype.createNewPromptBox=function () {
var scrollHeight=document.documentElement.scrollHeight+'px';
var scrollWidth=document.documentElement.scrollWidth+'px';
var body=document.body;

/*提示框阴影div*/
var div1=document.createElement("div");
div1.id=this.shadowId;
div1.style.position="absolute";
div1.style.background=" #000";
div1.style.zIndex="3001";
div1.style.left="0";
div1.style.top="0";
div1.style.opacity="0.6";
div1.style.display="none";
div1.style.height=scrollHeight;
div1.style.width=scrollWidth;

body.appendChild(div1);

/*-------------*/
var div9=document.createElement("div");
div9.id=this.divId;
div9.style.zIndex="3002";
div9.style.position="fixed";
div9.style.background=" #fff";
div9.style.left="0";
div9.style.top="0";
div9.style.bottom="0";
div9.style.right="0";
div9.style.width="400px";
div9.style.height="85px";
div9.style.display="none";
div9.style.borderRadius="4px";
div9.style.margin="auto";


/*   div9.style.display="none";*/


var div10=document.createElement("div");
div10.id=this.div1Id;
div10.style.padding="0 20px";
div10.style.overflow="hidden";
div10.style.height="42px";
div10.style.lineHeight="42px";
div10.style.color="#333";
div10.style.backgroundColor="#f8f8f8";
div10.style.cursor='move';
div10.style.textAlign="left";
div10.style.borderBottom="1px solid #eee";
div10.style.borderRadius="2px 2px 0 0";
div10.style.fontSize=" 14px";
div10.innerText=this.value;



var div11=document.createElement("div");
div11.style.borderTop="1px solid #2885d5";
div11.style.wordBreak="break-all";
div11.style.position="relative";
div11.style.overflowY="auto";
div11.style.overflowX="hidden";
div11.style.lineHeight="24px";
div11.style.textAlign="right";
div11.style.borderTop="1px solid #2885d5";
div11.style.fontSize="14px";


var input0=document.createElement("input");
input0.type="button";
input0.value="确认";
input0.style.color="#FFF";
input0.style.background="#2885d5 none repeat scroll 0 0";
input0.style.padding="0 15px";
input0.style.margin="6px 6px 0";
input0.style.cursor="pointer";
input0.style.fontWeight="400";
input0.style.height="28px";
input0.style.lineHeight="28px";

var this_=this;
input0.onclick=function () {

    this_.closeNewPromptBox();
};
div11.appendChild(input0);

div9.appendChild(div10);
div9.appendChild(div11);
body.appendChild(div9);



/*alert(this.value.length);
alert(this_.getStyle());*/
 };
 PromptBox.prototype.getStyle=function () {
if(document.getElementById(this.div1Id).currentStyle){

    if( document.getElementById(this.div1Id).currentStyle['width']=="auto"){
        return this.value.length*15;
    }else{
        return document.getElementById(this.div1Id).currentStyle['width'];
    }
    /* return document.getElementById(this.div1Id).offsetWidth ;*/
}else{
    if(getComputedStyle(document.getElementById(this.div1Id),false)['width']=="auto"){
        return this.value.length*15;
    }else{
        return getComputedStyle(document.getElementById(this.div1Id),false)['width'];
    }

}
};
PromptBox.prototype.closeNewPromptBox=function () {
document.getElementById(this.shadowId).style.display="none";
document.getElementById(this.divId).style.display="none";
  };


 PromptBox.prototype.showNewPromptBox=function () {
var scrollHeight=document.documentElement.scrollHeight+'px';
var scrollWidth=document.documentElement.scrollWidth+'px';

document.getElementById(this.shadowId).style.height=scrollHeight;
document.getElementById(this.shadowId).style.width=scrollWidth;


var this_=this;
this.value=arguments[0];

document.getElementById(this.div1Id).innerText=this.value;

var  width="";
if(this_.getStyle()<400){
    width=400;
}else{
    width=this_.getStyle();
}
document.getElementById(this.divId).style.width=width+"px";
document.getElementById(this.shadowId).style.display="";
document.getElementById(this.divId).style.display="";

      };
  PromptBox.prototype.removeNewPromptBox=function () {
document.getElementById(this.shadowId).parentNode.removeChild(document.getElementById(this.shadowId));
document.getElementById(this.divId).parentNode.removeChild(document.getElementById(this.divId));
   };
    /*PromptBox.prototype.showNewPromptBox=function () {

alert(this.value);
document.getElementById('promptBox__Div_01').style.display='';
document.getElementById('promptBoxValue_Div_01').innerText=this.value;
document.getElementById('promptBox_shadow').style.display='';

document.getElementById('promptBox__Div_01').style.width=getStyle(document.getElementById("promptBoxValue_Div_01"),'width');

 };*/
   /*提示框确认，就是关闭提示框*/

 //使用方法
  var promptBox=new PromptBox("new_prompt_box");
  promptBox.createNewPromptBox();