function timestemp_rand(){

let rand_len=4;

let timestemp=Date.parse(new Date())/1000;

var rdm=parseInt(Math.random()*10000+1).toString();

var length=rdm.length;

if(length<rand_len){

let cha=rand_len-length;

for(let i=0;i<cha;i++){

rdm=rdm+'0';

}

}

var _final=timestemp+'_'+rdm;

return _final;

}

//console.log(timestemp_rand())